Piperade

Reducing a sauce 95 recipes

• A steady simmer with the surface moving, never a rolling boil that throws it up the sides and scorches what is left on the base.
• Judged by behaviour rather than the clock: it coats the back of a spoon and holds a clean line when a finger is drawn through it.
• The drop in volume is visible against the side of the pan: there is a line to see, not a guess about whether anything has happened.
• Seasoned at the end and not the beginning, because salt concentrates at exactly the rate everything else does.
• Nothing is catching underneath: a spoon drawn across the base comes up clean, with no browned film building where the heat is fiercest.

Where it goes wrong It was seasoned at the start and then reduced by half. The salt concentrated along with everything else, so the sauce reaches perfect body and is too salty to serve. And the only remedy is to dilute it and reduce it all over again.

Sweating aromatics: soft, never browned 198 recipes

• No colour anywhere: tipped under the light the pieces are translucent to pale gold, with no tan edges, no brown tips, and no browned flecks suspended in the fat.
• The pan is quiet: a low steady hiss, not a crackle. A crackle means the moisture has gone and browning has already started.
• The largest piece pressed against the side of the pan collapses without resistance and with no crunch left at its centre.
• The fat is still clear and loose in the pan and the pan floor is clean: nothing caught, nothing browned on to deglaze, because there was never any fond to build.
• It tastes sweet and mild with no raw allium bite at the back of the throat, and none of the roasted sweetness that belongs to the next technique up the heat scale.

Where it goes wrong The heat was too high and nothing covered the pan, so the pieces took colour before they softened; the finished dish carries a roasty sweetness where it wanted a clean one, and the pieces are still firm at the centre under browned edges.