Machhere Jhol (Bengali Fish Curry)

Step 1
Bring the tomatoes, cumin, turmeric, salt, and water to a boil in a four quart saucepan; reduce heat to medium and maintain a simmer.

Step 2
Heat the oil in a skillet over medium-high heat; cook the fish in the oiled skillet until golden brown, 2 to 3 minutes per side. Transfer the fish to the saucepan.

Step 3
Heat a separate skillet over medium heat, and toast the mustard seeds, cumin seeds, black cumin seeds, fennel seeds, and fenugreek seeds until fragrant, just a few seconds. Stir the spices into the saucepan. Simmer until the flavors integrate, about 10 minutes more. Serve hot.