Romesco: The Catalan Sauce Built on a Dried Pepper
Romesco is Tarragona's sauce. According to Txaber Allué, quoted by 3Cat, the only written references to it are associated with El Serrallo, the city's fishermen's quarter. Its base is garlic, the dried red romesco pepper, hazelnuts and almonds, all pounded together into one paste. Tomato and bread can be added, and in this version vinegar and olive oil turn that paste into a brick-red sauce thick enough to hold a line on a plate. Every house in Tarragona has its own preferences, and one local chef, David Solé, says the romesco he makes today will not be the same as the one he makes tomorrow.
Two steps set this method apart. The pepper is soaked soft and its flesh is scraped from the skin, never blended in whole; in this recipe the skins are discarded. And the bread is fried in olive oil before it goes in, as in Tarragona recipes going back to the 1890s.
Ingredients, for about 2 cups
- 4 dried romesco peppers, or 2 dried ancho chiles, stemmed and seeded
- 2 ripe medium tomatoes (about 300 g), or 4 whole tinned peeled tomatoes, drained
- 1 head garlic
- 50 g (1/3 cup) blanched almonds
- 50 g (1/3 cup) hazelnuts
- 1 thick slice day-old country bread (about 40 g), crust removed
- 150 ml (2/3 cup) extra virgin olive oil, divided
- 2 tablespoons sherry vinegar or red wine vinegar
- 1/2 teaspoon smoked pimentón (if using ancho)
- Fine sea salt, about 3/4 teaspoon
- Optional: a splash of dry white wine or vi ranci
Method
- Soak the peppers. Cover the stemmed, seeded peppers with just-boiled water and leave them for 30 minutes, until they are completely soft. In Denver, give them 40 (see the altitude note below).
- Roast the tomatoes and garlic. Heat the oven to 400°F. Cut the top off the garlic head, rub the tomatoes and garlic with a teaspoon of the oil, and roast on a tray for 30 to 40 minutes, until the tomato skins split and blacken in spots and the garlic is soft enough to squeeze. Tinned tomatoes need only 20 minutes; they are there to lose water and pick up some char.
- Toast the nuts. Put the almonds and hazelnuts on a second tray in the same oven for 8 to 10 minutes. Snap one in half: they are done when golden all the way through, not just on the surface. Rub the warm hazelnuts in a kitchen towel to loosen the papery skins.
- Fry the bread. Warm 2 tablespoons of the oil in a small pan over medium heat and fry the bread for 1 to 2 minutes a side, until golden and crisp.
- Scrape the peppers. Drain the peppers, keeping the soaking water. Lay each one skin side down and scrape the soft red flesh away with the back of a knife. Discard the skins.
- Make the paste. Squeeze the garlic out of its skins and slip the tomatoes out of theirs. In a mortar or a food processor, work the garlic, nuts and torn fried bread to a coarse paste. Add the pepper flesh, tomato, pimentón if using, and salt, and keep going until it is nubbly but even. Romesco should have texture; it is not a purée.
- Mount with oil. With the processor running or the pestle moving, pour in the remaining oil in a thin stream. The sauce will go thick, glossy and a shade lighter. Stir in the vinegar, taste, and adjust with salt and vinegar until it is bright. If it is stiff, loosen it with a spoonful of the soaking water.
- Finish and rest. For the Tarragona finish, warm the sauce in a pan with a splash of white wine or vi ranci for 2 to 3 minutes. Either way, rest it at least 30 minutes so the flavors settle, and serve it at room temperature.
Why it went wrong
| Symptom | Cause | Fix |
|---|---|---|
| Bitter | The nuts or garlic scorched | Pull the nuts at golden, not brown |
| Greasy, oil separating | Oil added too fast, or too little bread and nut to hold it | Work in a spoonful of fried bread or ground nuts, then add the rest of the oil in a thread |
| Thin and runny | Too much soaking water, or watery tomatoes | Roast the tomatoes longer; add soaking water a spoon at a time and only at the end |
| Flat, tastes of nuts only | Not enough acid or salt | Another teaspoon of vinegar and a pinch of salt; taste again after it rests |
| Harsh garlic bite | Raw garlic went in | Roast the head until it is soft |
The pepper, and what to use instead
The base calls for the dried red romesco pepper. When it is hard to find, this recipe uses dried ancho chiles instead. Half a teaspoon of smoked pimentón gives the ancho version a Spanish accent. Spain's protected Pimentón de la Vera is dried for ten to fifteen days over oak and holm-oak fires, which is where its smoke comes from. A teaspoon of Jimmy Nardello pepper flakes (shop Jimmy Nardello pepper flakes) adds a sweet red-pepper note; Burlap & Barrel describes them as tasting of cherry and sun-dried tomato.
Notes and variations
The nuts. Almonds and hazelnuts together are the classic pair. The 3Cat report notes recipes that swap pistachios for the hazelnuts, and all-almond works too. Toasting is not optional: it is where the roasted, browned depth comes from, and the Browning Explained guide to Maillard and caramelization covers the chemistry. Nut oils can turn rancid in a warm cupboard, so taste one before toasting. Bar Nuts: The Complete Guide covers storage.
The vinegar. Sherry vinegar is the Spanish choice; red wine vinegar works too. The balsamic, sherry or red wine vinegar guide explains the difference, and Vinegar: The Complete Guide covers the rest.
The oil. About three-quarters of the oil goes into the sauce uncooked, so its flavor carries through. Use an extra virgin you like on its own, such as Capezzana (shop Capezzana).
The tomatoes. Out of season, good whole tinned tomatoes are a reliable alternative to fresh; Tinned Tomatoes and Passata: The Complete Guide covers reading the label.
Heat. The 3Cat report also mentions recipes that include heat; a dried hot chile in the soak adds it.
What it goes with. Grilled spring onions, leeks and asparagus; roast potatoes; grilled fish and shellfish; lamb chops; a hard-boiled egg; a slice of toasted bread on its own.
In Denver. Water boils at a lower temperature here, around 202°F instead of 212°F, so the soaking water starts cooler and the peppers can take longer to soften. Give them the extra ten minutes, and if they still resist, pour off the water and cover them with a fresh kettleful. The dry air also pulls moisture out of roasting tomatoes faster, so check them at 30 minutes, and you may need a little more soaking water to loosen the finished sauce than a sea-level recipe calls for. The full list of adjustments is in the Denver guide to cooking at altitude.
Keeping it. Keep romesco in a covered jar in the fridge with a film of oil on top. Bring it back to room temperature before serving; cold, it tastes dull and sets stiff.
Sources & Further Reading
- 3Cat: El romesco de Tarragona, un patrimoni dels pescadors del Serrallo (2025)
- Romescolab, Centre d'estudis del Romesco de Tarragona: A Brief History of the Romesco
- ICEX Foods and Wines from Spain: Pimentón de la Vera PDO
- Colorado State University Extension: High Elevation Food Preparation Guide
- Harold McGee, On Food and Cooking (Scribner, 2004), on nuts and on sauces thickened by particles
