Pescado a la talla

Step 1: Pat 3 ⅓ lb whole red snapper or sea bream dry, lay it open skin-side down and make 3–4 shallow cuts in the thickest part of the flesh. Rub with 2 tbsp lime juice and 1 tsp salt and keep in the fridge while you make the pastes.

Step 2: Toast 4 dried guajillo chillies and 1 dried ancho chilli in a dry pan over a medium heat for 15 seconds a side until fragrant, then soak in boiling water for 15 minutes until soft.

Step 3: Drain the chillies and blend with 2 cloves garlic, ¼ tsp ground cumin, ½ tsp dried Mexican oregano, 2 tbsp mayonnaise and 2–3 tbsp of the soaking water to a thick, smooth paste.

Step 4: Rinse the blender and blend 1 oz flat-leaf parsley, 1 oz fresh coriander, 2 serrano or green chillies, 1 clove garlic, 3 tbsp olive oil and ½ tsp salt to a thick green paste.

Step 5: Light a barbecue for medium-high direct heat (you can hold your hand above the grate for only 3–4 seconds), or heat an oven grill to high. Brush the grate or a hinged fish basket well with 2 tbsp vegetable oil.

Step 6: Spread the red paste over one half of the open fish and the green paste over the other half.

Step 7: Grill skin-side down for 12–15 minutes without moving it, until the skin is charred and crisp and the flesh has turned white about three-quarters of the way up. Under an oven grill, cook it flesh-side up on an oiled tray about 15 cm from the heat for 15–18 minutes. Common mistake: trying to flip the fish too early, before the skin releases; it tears and sticks.

Step 8: Turn the basket and grill flesh-side down for 2–3 minutes, just to char the pastes. The fish is done when the flesh at the thickest part near the backbone is opaque and flakes easily with a fork.

Step 9: Rest for 2 minutes, then slide onto a platter and serve with 2 limes, 12 warm corn tortillas and 1 red onion, letting everyone pull flakes from both halves.