Roast Pork with Mostarda: A Florentine Loin and a Mantuan Pear

Arista is Florence's pork loin, rubbed with garlic and rosemary, roasted until the fat on top turns crisp and amber, and carved thin. Mostarda is candied fruit from the Lombard plain: slices of pear or quince gone glassy in a thick syrup that carries a jolt of mustard. Its best-known partner is a pot of boiled meats. The two grew up on opposite sides of the Apennines. Put one on a fork with the other, though, and the case for them is immediate. The pork is salty and herb-crusted, and the pear tastes of honey for a second before the heat climbs into your nose like horseradish.

Geography makes the match look less natural than it is. The Mantua tourism office's booklet on the region's mostardas says the original formula was cooked grape must mixed with mustard seed, a hot sauce that ben si sposava con arrosti e carni, went well with roasts and meats. The must is still in the name: mostarda comes from mosto. The same booklet pairs Cremona's mixed-fruit mostarda with cotechino and cooked ham. Pork and mostarda already share a table in the Po valley. This recipe takes the pig out of the pot and puts it in the oven.

A name older than its legend

The story goes like this. In 1439 the Council of Florence brought churchmen from Constantinople to the city, and at a banquet one of them, Cardinal Bessarion, tasted the roast pork and pronounced it aristos, Greek for "the best." The Florentines took the compliment for the name of the dish and have called the loin arista ever since. Pellegrino Artusi helped make the tale famous in his cookbook.

The story is lovely, and it cannot be true. A Florentine convent's account book from 1287 already records a payment per j arista di porcho, for one arista of pork, a century and a half before any Greek bishop arrived. The Vocabolario dei testi gastronomici, an academic dictionary of historical Italian food language, traces the word to Latin arista, the bristly awn on an ear of grain, and suggests the name reached the pig's spine by a metaphor that ties it to fish bones and ears of grain. Tuscany's official tourism site leaves a door open for the Greeks: one alternative theory credits Greek merchants living in thirteenth-century Florence. If there is a Greek word in your roast, it may have come with traders, long before any theologian.

Keep the mustard off the burner

Everything in this recipe wants heat except the mostarda. The loin needs a hot start to brown, and the drippings need a hard boil to become sauce. The mostarda should stay out of both, and the reason is chemistry. Le Tamerici, a Mantuan mostarda maker, candies its sliced pears in syrup for several days and gives the mostarda its heat with a few drops of mustard essence. Harold McGee explains in On Food and Cooking that mustard's bite comes from volatile mustard oils, and that heat dissipates them. Simmer mostarda in a sauce and you are left with sweet pear and a faint memory of mustard. Stir it in once the pan is off the heat and the burn arrives whole.

The same logic rules out brushing the syrup over the roast as a glaze. In a hot oven the sugar can darken toward bitter before a loin is cooked through, and the mustard's heat cooks off. Fold a little mostarda into the finished sauce and put the rest on the board at room temperature.

145°F, and a little pink

The USDA's recommendation for pork was 160°F until May 2011, when it lowered its advice for whole cuts to 145°F followed by a three-minute rest. It said that pork cooked this way may still be pink and is safe to eat. Loin is lean, with little fat or connective tissue to cushion it, and as muscle heats past about 140°F its fibers contract and squeeze out juice. Fifteen degrees at the center decides whether a slice glistens or needs the sauce to get it down.

So the thermometer runs this recipe, not the clock. Take the roast out when the thickest part reads 145°F. During the rest the temperature holds or climbs a few degrees, and the center settles at a faint rosy blush. Ground pork is a different matter: its line stays at 160°F.

Ingredients

• 1.4 to 1.6 kg (3 to 3 1/2 lb) boneless center-cut pork loin roast with a thin fat cap, tied at intervals
• 14 g (about 2 1/2 teaspoons) fine sea salt, roughly one percent of the meat's weight
• 3 garlic cloves
• 2 tablespoons fresh rosemary leaves
• 1 teaspoon fennel seed, optional, such as Burlap & Barrel's Lucknow fennel (shop Lucknow Fennel Seed)
• 1 teaspoon black peppercorns, freshly ground
• 2 tablespoons extra virgin olive oil
• 120 to 240 ml (1/2 to 1 cup) water, for the roasting pan
• 180 ml (3/4 cup) dry white wine
• 1 jar (about 140 g / 4.9 oz) pear mostarda, such as Casa Forcello Pear Mostarda (shop Casa Forcello Pear Mostarda), or 2/3 cup homemade
• 1 teaspoon seed-style Dijon mustard, optional, such as Edmond Fallot's (shop Edmond Fallot Seed-Style Dijon)

Ask for a center-cut loin with its fat cap left on, about a quarter inch thick. That thin layer of fat crisps in the oven and is the part people fight over. A bone-in rib roast works with the same method and the same target temperature; it just takes longer to get there. For the mostarda, a Mantuan-style pear, sliced thin and packed in syrup, chops neatly into a sauce. The Casa Forcello producer guide has the story of the house. A Cremona-style jar of mixed whole fruit works too, as long as you chop it. For a batch of your own, the three-day pear mostarda recipe makes about three cups.

Method

1. Salt it a day ahead. Pat the pork dry, rub the salt over every surface including the ends, and set it on a rack over a plate in the refrigerator, uncovered, for 12 to 24 hours. The salt has time to travel inward and season more than the crust, and it loosens the muscle proteins so they hold on to more of their juice. The uncovered night also dries the surface, and a dry surface browns where a wet one only steams. The salting guide explains why fine salt measures differently from flaky.
2. Make the paste and stuff the loin. An hour before roasting, take the pork out of the refrigerator and heat the oven to 425°F (220°C). Pound the garlic, rosemary, fennel and pepper with the oil in a mortar (or chop them together very finely) into a rough green paste. With a thin knife, cut eight or ten deep slits into the lean sides and ends of the loin and push most of the paste into them with a finger. Smear the rest thinly over the sides. Keep it off the fat cap, where garlic would scorch in the hot first stage. Score the fat in a shallow crosshatch without cutting into the meat.
3. Start hot. Set the loin fat side up in a roasting pan or skillet only slightly bigger than the meat, and roast for 15 minutes, until the fat is sizzling and starting to turn gold. A pan with a lot of empty space lets the drippings spread thin and burn, and they are your sauce.
4. Finish gently. Lower the oven to 325°F (165°C) and pour about 120 ml (1/2 cup) water into the pan around the roast, not over it. Start checking with an instant-read thermometer 30 minutes after lowering the heat, pushing the probe into the center of the thickest part. Expect roughly 35 to 60 minutes at this stage for a 3-pound loin, depending on shape and how cold the meat started. Take it out at 145°F (63°C). Each time you check, look at the pan. If the water has cooked off and the drippings are darkening at the edges, add another splash.
5. Rest. Move the roast to a carving board, tent it loosely with foil, and leave it for 15 minutes. The center will rise a few degrees, and the meat firms up enough to lose less juice when you carve it.
6. Make the pan sauce. Tip the pan and spoon off all but about a tablespoon of fat. Set it over medium heat (or scrape everything into a small saucepan if your roasting pan can't go on a burner), pour in the wine, and scrape up every browned bit with a wooden spoon. Boil until the liquid has reduced by about half and tastes rounded rather than sharp, three to five minutes. Pour in whatever juice has collected under the resting roast, then take the pan off the heat and let it stop bubbling.
7. Add the mostarda off the heat. Lift out about a third of the mostarda slices, chop them finely, and stir them into the warm sauce with 2 tablespoons of the syrup from the jar. Add the Dijon if you want more heat than your mostarda brings. Taste: the sauce should be savory first, lightly sweet, with a clean prickle at the finish. Add salt if it needs it. Do not return it to the burner.
8. Carve and serve. Snip and pull away the strings. Carve across the grain into slices about 6 mm (1/4 inch) thick. The paste-filled slits will show as green seams in each slice. Fan the slices on a warm platter, spoon the sauce over, and set the remaining mostarda slices beside them at room temperature so everyone can add more.

In Denver

Oven roasting is one of the few things altitude leaves alone. Colorado State University Extension and New Mexico State University's extension guide agree that sea-level oven temperatures and times work for dry-roasted meat. The 145°F target doesn't change either, because the thermometer measures the meat, not the air. The pan is where Denver shows up. Water boils at about 202°F at 5,000 feet (CSU's table says 203°F), and CSU notes that the region's low humidity makes moisture evaporate faster during cooking. The water under the roast can disappear before the meat is done, leaving drippings to scorch. Start with the full cup of water rather than half, and check the pan each time you check the meat. Judge the wine reduction by eye and taste, not by minutes. For the rest of the numbers, see the Denver altitude cooking guide.

When it goes wrong

At the table

Carve at the table if you can. A loin with a green-seamed cross section and a burnished cap is a good thing to watch being cut. Serve the mostarda at room temperature, and put out less than you think: a tablespoon or so per person beside the sauce is plenty, and one small jar covers both for six. Soft polenta from the polenta recipe catches the sauce well. A bitter green salad dressed sharply resets the palate between bites of sweet and rich.

Leftover arista slices paper thin when cold. Lay it on good bread with a slice or two of mostarda and you have the lunch this whole recipe was secretly building toward.

The Ambrosian Pantry is at 263 Josephine Street in Cherry Creek, Denver, where visitors can ask staff questions in the shop, and products ship across the continental U.S. from theambrosianpantry.com.

Sources & Further Reading

• Turismo Mantova, "Le Mostarde" (official booklet on the Cremona, Mantova and Voghera styles)
• Treccani, Vocabolario, "mostarda"
• Le Tamerici, Mostarda Mantovana: method
• Le Tamerici, Pear Mostarda: ingredients and pairings
• Vocabolario dei testi gastronomici (AtLiTeG), "arista"
• Visit Tuscany, "Arista: Tuscan-Style Roast Pork"
• Italiani.it, "Arista di maiale, da un curioso episodio storico alla tavola"
• CIDRAP, University of Minnesota, "USDA: 145 degrees is safe temp for pork" (May 2011)
• Food Safety News, "USDA's New Recommended Pork Cooking Temp: 145°F" (May 2011)
• Iowa Pork Producers Association, "How to Roast a Boneless Pork Loin"
• Colorado State University Extension, High Altitude Food Preparation
• New Mexico State University Extension, Guide E-215, High-Altitude Cooking
• Harold McGee, On Food and Cooking (Scribner, 2004), on meat proteins and juiciness, salting, browning, and mustard's pungency