Tiritas de Pescado Zihuatanejo

Ingredients

• 500 g very fresh sierra, mackerel or snapper fillet, skinned
• 200 ml lime juice, from about 8 limes
• 5 serrano chillies, thinly sliced
• 1 red onion, thinly sliced
• 1 tsp dried Mexican oregano
• 1 tsp fine salt
• 1/2 tsp freshly ground black pepper
• 1 avocado, sliced
• 8 corn tostadas
• hot sauce, to serve

Before you cook

• Chill the fish fillet in the freezer for 15 minutes so it firms up enough to slice cleanly.
• Slice the red onion into paper-thin half moons, rinse them under cold water for 20 seconds and drain them well.
• Slice the serranos into fine rings, keeping the seeds in if you want the full Guerrero heat.
• Squeeze the limes and slice the avocado.

Steps

1. Lay the chilled fillet on a board and run your fingertips along it, pulling out any pin bones you find.
2. Cut the fillet across the grain into strips about 5 cm long and 5 mm wide, using a very sharp knife.
3. Put the strips in a glass or ceramic bowl, never a metal one.
4. Season the fish with the salt and pepper and turn it gently with your hands.
5. Pour the lime juice over so the fish is just submerged.
6. Add the sliced onion and the serranos, then crush the oregano between your palms as you scatter it in.
7. Turn everything once, cover the bowl and refrigerate it for 15 minutes.
8. Check the fish: it should be opaque white at the edges and still faintly translucent in the middle.
9. Taste for salt and lime, and add more of either if it tastes flat.
10. Pile the tiritas onto tostadas with some of their juice, lay avocado on top and pass the hot sauce.