Salsa Negra Vasca

Salsa negra vasca belongs to the Basque coast, where it is the sauce for txipirones en su tinta, small squid served in a glossy black gravy of onion, wine, fish juices, and their own ink. The colour is dramatic, but the cooking isn't. What separates it from a merely ink-coloured sauce is the slow, sweet onion foundation underneath.

The method that decides it happens before anything black enters the pan. I cook the onion and green pepper low until they have collapsed, turned dark gold, and become almost jammy. Only after the tomato and wine have reduced do I blend the base and add the ink diluted with stock. Ink dropped onto a bare hot pan catches and turns bitter, while hurried onion stays sharp. Give the sofrito its time and the sauce comes out deep, gently sweet, and cleanly marine.

If squid ink is difficult to find, use pasteurized cuttlefish ink sachets. That is the sensible substitute, though cuttlefish ink can taste a little stronger and saltier, so hold back the final salt. A good canned whole tomato is better than a pale fresh one in winter; it gives a slightly rounder sauce, but keeps the proper balance. No hace falta haber pisado España. The note in my Margin is short: taste for salt after the ink, never before.