- 1 pound fresh sea bass, mahi-mahi, or other firm-fleshed white ocean fish, cut into cubes about 1 inch square
- ½ small onion, very thinly sliced
- 1–2 serrano chiles, seeded and chopped
- Juice of 4 juicy limes
- 1 teaspoon salt
Combine all ingredients in a non-reactive bowl and stir to mix well. Cover with plastic wrap and let marinate for 1 hour, then serve with tortilla chips or saltine crackers.