Appetizer: Mexico – Baja California – Tostadas de Mariscos (Seafood Tostadas)

Serving Size: 6

Approximate Time

Prep 35 min

Cook 15 min

Additional 20 min

Total 1 hr 10 min

Ingredients

- 6 tostada shells
- 8 oz (225 g) raw shrimp, peeled and deveined (about 12 medium)
- 8 oz (225 g) cooked octopus, sliced (approx. usable weight)
- 8 oz (225 g) firm white fish (corvina, sea bass, or similar), cut into 1/2-inch (1.2 cm) cubes
- 3/4 cup (180 ml) fresh lime juice (about 6–8 limes)
- 1/4 cup (60 ml) fresh orange juice (optional, for balance)
- 1 cup (150 g) diced Roma tomatoes (seeds removed)
- 1/2 cup (75 g) finely diced red onion
- 1/4 cup (15 g) minced fresh cilantro leaves
- 1–2 serrano chiles, minced (adjust to taste)
- 1 ripe avocado, sliced
- 2 tbsp (30 ml) extra-virgin olive oil or neutral oil
- 1/4 cup (60 ml) Mexican crema or sour cream
- Salt to taste
- Freshly ground black pepper to taste
- 1/2 cup (40 g) thinly sliced radishes (optional, for crunch)
- Lime wedges, for serving

Quick-pickled red onion
- 1/2 small red onion, very thinly sliced (about 1/2 cup / 50 g)
- 1/4 cup (60 ml) white vinegar
- 1 tbsp (12 g) granulated sugar
- 1 tsp (5 g) kosher salt
- 2 tbsp (30 ml) water

Instructions

Short Description:
Crisp tostada shells topped with a bright Baja-style mix of local seafood—shrimp, octopus, and firm white fish—marinated in lime with tomato, onion, cilantro and avocado for a refreshing coastal starter.

Regional Notes:
This Baja California version highlights fresh regional seafood (shrimp, octopus, and corvina/other firm white fish) lightly cured or cooked and dressed simply with lime, cilantro, and raw vegetables. Unlike inland ceviches, Baja tostadas emphasize a crunchy tostada base and may include a drizzle of crema and quick-pickled onion typical of coastal northern Mexico.

1. Make the quick-pickled red onion: combine vinegar, sugar, salt, and water in a small bowl; stir until sugar and salt dissolve. Add the thinly sliced red onion, press down so onion is submerged, and let sit at room temperature at least 15 minutes (or refrigerate up to 2 hours). Drain before using.
2. Prepare the shrimp: bring a medium pot of salted water to a gentle boil. Add shrimp and cook just until pink and opaque, about 1.5–2 minutes depending on size. Immediately transfer to an ice bath to stop cooking, then drain and roughly chop into bite-sized pieces.
3. If using fresh uncooked firm white fish for ceviche-style curing: place the cubed fish in a nonreactive bowl and pour over the lime and orange juices so fish is submerged. Cover and refrigerate 15–20 minutes, or until the fish turns opaque and is firm to the touch. Drain the fish, reserving a tablespoon of the citrus if desired to add back for brightness.
4. Prepare the octopus: if not already cooked, simmer cleaned octopus in gently simmering water with a bay leaf and a pinch of salt until tender (about 30–45 minutes for small tentacles). Cool, then slice. If using pre-cooked octopus, slice and warm briefly in a skillet with a teaspoon of oil if you prefer it slightly warm.
5. Combine the seafood: in a bowl, gently toss the chopped shrimp, sliced octopus, and drained citrus-cured fish with diced tomatoes, diced red onion, minced serrano, cilantro, 2 tablespoons lime juice (from earlier), olive oil, salt and pepper to taste. Adjust heat and seasoning.
6. Assemble tostadas: lay out tostada shells. Spoon an even portion of the seafood mixture onto each shell (about 3–4 oz / 85–115 g seafood per tostada). Top with sliced avocado, a spoonful of quick-pickled onion, thinly sliced radish, and a small drizzle of Mexican crema.
7. Finish and serve: garnish with additional cilantro leaves and a lime wedge on the side. Serve immediately so tostada shells remain crisp.