Warm a dry skillet over medium heat. Add dried red chiles, cumin, mustard seeds, black peppercorns, coriander seeds, cloves, cardamom and cinnamon. Toast, shaking the pan, until fragrant and the chiles darken slightly, about 2–3 minutes. Remove from heat and let cool. Grind to a fine powder in a spice grinder or mortar and pestle.

Make masala paste

In a blender, combine the ground toasted spices, tamarind paste, vinegar, garlic, ginger, chopped red onion, chopped tomato, sugar, salt and 1 tablespoon vegetable oil. Blend to a smooth, slightly coarse paste, adding 1–2 tablespoons of water if needed to achieve a spreadable consistency (about 30–45 seconds). This is the balchão masala.

Taste the masala and adjust salt, sugar or tamarind to get a tangy, slightly sweet and hot balance typical of Goan balchão.

Marinate fish and shrimp: Place snapper pieces and shrimp in a bowl. Add 3–4 tablespoons of the prepared balchão masala, gently toss to coat, and set aside to marinate for 15–20 minutes while you prepare the sauce base.

Seafood & Main Sauce

Prepare sauce base

Heat 2 tablespoons oil in a deep sauté pan or Dutch oven over medium heat. Add 1/2 teaspoon mustard seeds and let them pop (10–20 seconds). Add curry leaves and slit green chilies; fry briefly until fragrant (about 30 seconds).

Add the remaining balchão masala from the marinade (scrape all into the pan). Sauté the masala, stirring constantly, for 3–4 minutes until oil begins to separate from the paste and the raw smell cooks off.

Stir in turmeric and red chili powder and cook 30 seconds. Pour in 200 ml water, scrape up any browned bits, and bring to a gentle simmer. Simmer 5–6 minutes to slightly reduce and concentrate flavors.

Cook seafood

Gently add the marinated snapper pieces into the simmering sauce in a single layer. Spoon sauce over the fish, cover and simmer very gently for 6–8 minutes, until the fish is nearly cooked through. Add the red shrimp, nestling them into the sauce. Pour in the coconut milk, stir gently to combine, and simmer uncovered 3–4 minutes until shrimp turn pink and fish is cooked through (internal temperature ~63°C/145°F). Do not over-stir to avoid breaking the fish.

Adjust seasoning with 3/4 teaspoon salt (or to taste). If the balchão needs more tang, stir in up to 1 teaspoon extra tamarind paste or 1 teaspoon vinegar. If too sharp, add a pinch of sugar.

Finish with 2 tablespoons chopped cilantro and remove from heat. Let the curry rest 5 minutes; flavors will meld.

To Serve

Spoon cooked basmati rice into shallow bowls, ladle the seafood balchão on top or to the side, and garnish with additional cilantro and lime wedges. Serve with warm house-made flatbread to soak up the sauce.

Leftovers: Refrigerate in an airtight container for up to 2 days. Gently reheat on low with a splash of water or coconut milk to loosen the sauce.