On the face of it, Vizcaina sauce is a conspicuously simple sauce which requires only a handful of readily available ingredients, the signature one being sweet red peppers. However, such a perfunctory assessment does enormous disservice to a Northern Spanish icon as steeped in local culture as it is imbued with flavor. While Vizcaina has its cultural roots in the Basque region, it perks up dishes across the Spanish-speaking diaspora, making footfall in South America, Mexico and even the Philippines.
Vizcaina sauce takes its name, and its intrinsic character, from the Biscay region of northern Spain in the heart of Basque country, a region famous for its gastronomy and top chefs. Indeed, the area between Bilbao and San Sebastian compares favorably with Paris for the number of Michelin starred restaurants. Vizcaya is the Basque name for the sprawling bay along the Atlantic coast of northern Spain and western France. The region's eponymous sauce found its perfect pairing when Basque fishermen returning from the Grand Banks off Newfoundland brought back salt cod, establishing a culinary classic directly derived from Basque seafaring culture.
The exact ingredients of Vizcaina sauce are themselves a source of controversy. Not up for debate, however, is the main ingredient, red choricero peppers that grow in the region and are traditionally harvested at the end of summer and dried in farmhouses. These sweet peppers, one of the coloring agents for chorizo sausage, are particularly associated with the area around Guernica. The sauce then incorporates onions, garlic, olive oil, chorizo and a final flourish of parsley. Some chefs extend the sauce to include tomatoes, but others argue this would stray into standard sofrito territory, or make the sauce closer to a Romesco.
Although dried peppers are traditionally used, fresh red peppers with the seeds removed are acceptable to start with instead. The peppers impart the distinctive lurid orange and red color to the sauce, and render a warm, smoky flavor. Once the pepper, onion and garlic are sweated in olive oil, a trick is to add broth from the salt cod and to blend. If tomatoes are used, the sauce can be refrigerated for up to two days and actually improves in flavor as the acidity turns to sweetness. Vizcaina's Basque character stems from respecting the simplicity of the ingredients and focusing on the flavors with a minimum of posturing.
Basque food is one of those regional cuisines which are frequently appropriated into the national roster, and salt cod in a Vizcaina sauce is frequently cited as a standard Spanish dish to rank alongside paella. While the salt cod dish is particularly popular around the Catholic Lenten season, the sauce also pairs throughout the year with other fish, vegetables, pork and even snails. Pork shank in a Vizcaina sauce is a popular pairing. Vizcaina can either feature as a main dish or served in a porcelain spoon as a typical Basque pintxo, or tapas dish where its intense, exquisite flavor is properly showcased.