Oven-Roasted Fish with Onion, Lemon, Fenugreek & Cilantro (Mahi-e Shekam Por)

To prepare filling: Heat 3 tablespoons oil in a large skillet over medium heat. Add thinly sliced onion and cook, stirring often, until starting to brown, 3 to 6 minutes. Reduce heat to medium-low and cook, stirring often, until the onion is dark golden brown, 10 to 15 minutes.

Add cilantro, fenugreek, garlic, ginger, tamarind, tomato paste, turmeric, cayenne (or crushed red pepper) and 1/2 teaspoon salt. Cook, stirring occasionally, until the cilantro is very soft, 1 to 2 minutes. Remove from heat.

To prepare fish: Position rack in upper third of oven; preheat to 400 degrees F. Line a rimmed baking sheet with foil.

Place half of the lemon and onion rounds in a single layer in the middle of the prepared pan. Rub each fish inside and out with oil and salt. Divide the filling between the fish, spooning it into the cavity; stuff with the remaining lemons and onions. Lay the fish side by side on the lemons and onions on the pan. Drizzle water around them and cover the pan tightly with foil.

Bake for 12 minutes. Remove the foil and continue baking until the fish are just cooked through, about 15 minutes more.