Romesco

Steps

1. roast40 min
   400°F / 205°C, cut faces up, one uncrowded layer, garlic pulled at 25 minutes
   tomatoes + whole garlic head + 2 tbsp of the olive oil, until the tomato skins have blistered and blackened in patches and the halves have visibly slumped and given up their water. This is a concentration step: a raw tomato is ninety-odd percent water and would thin the sauce to soup, and the browning at the blistered edges is flavour that cannot be got any other way. Pull the garlic well before the tomatoes — it is soft and sweet at twenty-five minutes and acrid by forty, and burnt garlic is not something the rest of the sauce can outvote. Crowding the pan is the failure here: tomatoes packed tight steam in their own liquid and never blister.
2. rest30 min
   submerged in boiling water, covered, weighted with a saucer
   ñora peppers in just-boiled water until fully pliable, then split them and scrape the softened flesh from the skin with the edge of a spoon — the flesh goes in the sauce, the skin goes in the bin. The skin is a tough cuticle that no home processor will ever break down, and left in it shows up as leathery flecks in an otherwise fine sauce. Expect about a tablespoon of pulp from three peppers; it looks like nothing and carries most of the sauce's depth.
3. toast5 min
   dry pan, medium, shaken constantly, off the heat before they look done
   almonds + hazelnuts until the surface is straw-gold and they smell of nut rather than nothing. Nuts hold a lot of heat for their size, so they keep cooking in the pan after the flame is out — take them to just short of the colour you want and tip them onto a cold plate. The window between golden and bitter is under a minute and there is no recovering a scorched batch: the bitterness goes right through the finished sauce and cannot be sugared, salted or acidulated out.
4. fry4 min
   2 tbsp olive oil, medium, turned once
   torn stale bread until crisp and gold on both faces, then drained. Bread is not filler here, it is the structure — its starch and the ground nuts together are what hold the olive oil in suspension, and a romesco made without it separates into a slick of oil over a sediment of solids within the hour. Stale bread is specified because a fresh crumb is full of water and will fry soggy rather than crisp. It burns on the same schedule as the nuts; watch it the same way.
5. mix4 min
   food processor, pulsed in bursts, nuts and bread ground first
   toasted nuts + fried bread pulsed to a coarse, sandy crumb, then + roasted tomato flesh + the squeezed-out roasted garlic + scraped ñora pulp + sherry vinegar + salt, pulsed only until combined. Grinding the dry solids first is what gives you control over the grain; dropped into a wet mass they simply refuse to break down evenly and you end up over-running the machine to chase them, which is how a textured sauce becomes a smoothie. A processor is the right tool — a blender's vortex drives everything past the texture you want, and the mortar the sauce was invented in is coarser than either.
6. emulsify3 min
   motor running, oil poured in a thin steady stream, stopped while still slightly grainy
   + the remaining olive oil, added last and slowly until the sauce turns from a rubble into a thick, spoon-coating mass with a brick-orange sheen. Oil poured in at the start coats every particle before it can be ground and the sauce stays loose and greasy no matter how long it runs; added last and in a stream it is broken into droplets and trapped between the nut and bread solids, which is what gives romesco its body without any egg or dairy. Stop while you can still feel grain on the tongue. A smooth purée is the standard mistake and it reads as thin and pasty next to the correct texture.
7. rest30 min
   covered, room temperature — better still overnight in the refrigerator
   the finished sauce, left to sit before it is served. The vinegar's edge is sharp on the hour and rounded by the next day, and the roasted garlic and pepper flesh keep bleeding into the oil while it stands. Taste and correct salt and vinegar after the rest, not before, because both read differently once the sauce is cold. It keeps five to ten days refrigerated under a film of oil, and freezes for several months.