Aji Amarillo Sauce

Place whole aji amarillo chiles directly over a gas flame or under a broiler. Turn with tongs every 30 seconds until the skin is blistered and blackened in patches all over, about 3-4 minutes total. Transfer immediately to a bowl and cover tightly with plastic wrap or a plate to trap steam. Let steam for 10 minutes — the trapped heat loosens the skin from the flesh.

Peel the charred skins off under running water or by rubbing gently with your fingers. Cut off the stem end. Split the chile lengthwise and scrape out the seed membrane with a spoon — remove all seeds for mild heat, leave one chile's worth of seeds if you want the sauce to burn. Warning: do not touch your eyes; the capsaicin is concentrated in the membrane.

Warm 1 tablespoon of the oil in a small skillet over medium heat. Add the chopped onion and cook, stirring occasionally, for 5-6 minutes until translucent and beginning to catch golden colour at the edges. Add the garlic cloves and cook for a further 2 minutes until fragrant and soft. Do not brown — you want sweetness, not caramel bitterness.

Combine the peeled chiles, cooked onion and garlic, lime juice, and huacatay in a blender. Blend on high for 60 seconds until completely smooth. Scrape down the sides and blend again. The puree should be a vivid, uniformly orange paste with no visible green flecks of herb remaining.

With the blender running on medium speed, drizzle the remaining oil through the feed cap in a very thin, slow, steady stream — this should take at least 60 seconds. The sauce will visibly thicken and lighten as the oil emulsifies into the puree. If no feed cap, add oil in four small additions, blending 10 seconds between each.

Add salt in small increments, tasting after each addition. The salt should amplify the fruity, chile heat without making the sauce taste salty. A final squeeze of lime (optional) can brighten the sauce if the chiles were particularly sweet. Adjust heat level: if too mild, add a pinch of cayenne; if too hot, blend in an additional half of a peeled, roasted sweet red pepper.