Entree: Mexico – Baja California, Northern Mexico – Caldo de Siete Mares (Seven Seas Soup)

Serving Size: 6

Approximate Time

Prep 30 min

Cook 40 min

Total 1 hr 10 min

Ingredients

- 1 lb (454 g) fish frames/heads for stock OR 8 cups (1.9 L) prepared fish stock
- 2 tbsp (30 ml) vegetable oil
- 1 medium white onion, halved (about 6 oz / 170 g)
- 3 roma tomatoes (or 2 cups / 280 g chopped), charred or roasted
- 3 cloves garlic, smashed
- 2 medium carrots, peeled and sliced (about 8 oz / 225 g)
- 2 stalks celery, chopped (about 3 oz / 85 g)
- 1 medium Yukon Gold potato, peeled and diced (about 8 oz / 225 g)
- 1 ear corn, cut into 6–8 rounds (elote)
- 1 serrano chile, sliced (optional for heat)
- 1 tsp (5 ml) whole black peppercorns or ground black pepper
- 2 bay leaves
- 1 tsp (1 g) dried Mexican oregano (or regular oregano)
- 1 lb (450 g) firm white fish fillet (corvina, sea bass, or halibut), cut into 1-inch chunks
- 12 large shrimp, peeled and deveined, approx. 8 oz (225 g)
- 8 oz (225 g) cooked octopus, sliced
- 16 clams (manila or littleneck), scrubbed, approx. 1 lb (450 g)
- 1 tsp (5 g) kosher salt, plus more to taste
- 2 tbsp (30 ml) fresh lime juice (about 1 lime)
- 1/4 cup (15 g) chopped fresh cilantro for garnish
- Lime wedges for serving
- 1 1/2 cups (300 g) cooked white rice OR warm corn tortillas for serving

Instructions

Short Description:
A hearty Baja California seafood soup that combines a clear, flavorful fish broth with an assortment of fresh seafood—fish, shrimp, octopus, and clams—plus vegetables and lime for brightness. Served with rice or warm corn tortillas to make a complete main-course meal.

Regional Notes:
This Northern Mexico / Baja version emphasizes a clear, tomato-bright seafood broth built from fish frames or prepared fish stock and a mix of locally available seafood (firm white fish, shrimp, octopus, clams). Compared with coastal soups in other regions, the Baja style often keeps the broth light and citrus-forward, relying on the freshness and variety of seafood rather than heavy chiles or creams.

1. Make the stock: In a large pot, combine the fish frames/heads (if using) with 8 cups (1.9 L) water, half the onion, 1 carrot, 1 celery stalk, 1 bay leaf, and a few peppercorns. Bring to a gentle simmer and cook 20–30 minutes. Strain and reserve 6–8 cups (1.4–1.9 L) clear fish stock; discard solids. If using prepared fish stock, heat it in the pot and skip this step.
2. Prepare the tomato base: Char the roma tomatoes (and the remaining half onion and 1 garlic clove) directly over a flame or under a broiler until blackened. Transfer to a blender with the remaining garlic clove and 1/4 cup (60 ml) water and puree until smooth. Set aside.
3. Sauté aromatics: In the same large pot, heat 2 tbsp (30 ml) vegetable oil over medium heat. Add the remaining sliced onion, sliced carrot, chopped celery, and optional serrano. Sauté until softened, 4–5 minutes. Add the tomato puree and cook, stirring, 3–4 minutes to meld flavors.
4. Build the soup: Pour the fish stock into the pot with the tomato-vegetable mixture. Add the diced potato, corn rounds, remaining bay leaf, dried oregano, and pepper. Bring to a gentle boil, then reduce heat and simmer until potatoes are just tender, about 8–10 minutes.
5. Add the seafood: Add the fish chunks first and simmer 3 minutes. Then add the shrimp, sliced octopus, and scrubbed clams. Simmer gently until shrimp are opaque and clams have opened, about 4–6 minutes more (discard any clams that remain closed). Avoid over-stirring so delicate fish stays intact.
6. Season and finish: Taste and adjust salt (start with 1 tsp / 5 g). Stir in 2 tbsp (30 ml) fresh lime juice and about half the chopped cilantro. Remove bay leaves.
7. Serve: Ladle the caldo into deep bowls over 1/4 cup (50 g) cooked rice per serving or alongside warm corn tortillas. Garnish with remaining cilantro and lime wedges.