Step 1

Preheat a 5-to-6-quart slow cooker. Combine coconut, chiles, coriander seeds, onion, turmeric, ginger, garlic, tamarind, cumin, fenugreek, curry powder, and 1 teaspoon salt in a food processor; puree until a paste forms.

Step 2

Transfer to a saucepan, add coconut milk, and bring to a boil. Transfer coconut mixture to slow cooker. Cover and cook on high until slightly thickened, 2 hours (or on low 4 hours).

Step 3

Season fish with salt and add to slow cooker, submerging in curry sauce. Cook on low until fish is flaky but not falling apart, about 20 minutes. Serve, sprinkled with cilantro.