Salsa Bizkaína (Spanish Sweet Pepper Sauce)

This is one of those sublime sauces that changes in each cook’s hands. There’s a lot of discussion about whether salsa bizkaína should have tomatoes; I use tomato but judiciously, as too much cheapens the sauce. You can use this sauce on potatoes, oil-poached salt cod, or tripe, but my favorite way to enjoy it is with snails, because the snails are just an excuse to eat the sauce, which is doped up with bacon and chorizo.

10 dried choricero or guajillo peppers, or 2 cups choricero pepper paste
3 Tbsp. extra-virgin olive oil
8 cups Spanish onion, thinly sliced
1 bay leaf
4 cloves garlic, thinly sliced
1 Tbsp. kosher salt
4 oz mixed chorizo and/or jamón ends, diced small
1 tsp. sweet Spanish paprika
1 cup canned whole plum tomatoes
ground Cheyenne chile, if using choricero peppers

Heat a dry frying pan over medium heat, add the peppers, and toast, turning once, for about 30 seconds total, just until pliable. Remove from the heat, trim away the stems, tear the peppers open, and shake out their seeds. Place the peppers in a heatproof bowl, add boiling water to cover, and top with a weight to keep them submerged in the water. Let the peppers soak for about 20 minutes until they are plump and you can scrape their pulp from their skin with a spoon. Scrape the pulp into a bowl, discard the skin, and reserve the pepper pulp and soaking water separately.

In a 3-qt saucepan, gently heat the oil over low heat. Add the onion, bay leaf, and garlic, coat them with the oil, and cook for 5 minutes, stirring. Add the salt, cover, and cook over low heat for 10 minutes. Uncover, stir well, add the chorizo and jamón, and cook, stirring occasionally, for 5 minutes. Re-cover and continue to cook for another 20 minutes, until the onions are sweet and wilted.

Uncover the pan and continue to cook over low heat, stirring, for about 5 minutes, until the onion is very sweet and uniformly golden but not brown. The goal here is to melt the onion. Add the reserved pepper pulp and paprika and cook, stirring, for 5 minutes. Raise the heat to medium-high and add the tomatoes, crushing them with your hands as you drop them in. Cook, stirring, for about 8 minutes. Remove from the heat and let cool and rest for 20 minutes.

If you have used choricero peppers, you can add some Cheyenne chile for punch; if you have used guajillos, the sauce should have plenty of punch. Working in batches, transfer the sauce to a blender or food processor and puree while it is still warm but not hot. If the sauce is too thick, thin it with the reserved pepper-soaking water. Use immediately, or transfer to airtight containers and refrigerate for up to 3 days or freeze for up to 3 months.

Makes about 6 cups.