Grilled yellowtail with all-grilled tomato and nopal salsa

Lay ripe tomatoes, fresh green chilies and knob onions on the grill; add nopal cactus paddles, drizzling a little olive oil on the cactus and onions.

For the marinade, crush and finely chop about six cloves of garlic; combine in a bowl with olive oil, the juice of key limes, sea salt and a little black pepper.

Stir the marinade with the fish and leave it to marinate while making the salsa.

Skin the chilies or not, cut off the tops, scrape out the seeds and chop together with the tomatoes, skinned if wanted.

Slice the knobs of the onions into rings, discarding the crisped tops; chop the nopales, cooked completely soft.

Season the salsa with Mexican oregano crushed between the palms and sea salt.

Grill the well-oiled fish without flipping too early: turn it when it moves freely and is crusted, and cook until a little less resilient and flaking under firm pressure.

Serve on a tostada with the salsa, topped with crunchy chicharron.