How to Make It
Lay the catfish steaks in a large nonreactive baking dish. Mix 1/4 cup of the Roasted Tomatillo–Chipotle Salsa with 1 tablespoon of the oil, the brush the mixture on both sides of the fish. Cover and refrigerate for at least 2 hours or for up to 6 hours.
Heat a large nonreactive skillet over moderate heat. Add the garlic and toast, turning occasionally, until softened and blackened in spots, about 15 minuts. Let cool slightly, then peel.
Heat the remaining 1 tablespoon oil in the skillet. Add the onion and cook over moderately high heat, stirring occasionally, until beginning to brown, about 5 minutes. Add the remaining 1 3/4 cups salsa to the skillet along with the cumin, pepper and toasted garlic cloves. Cook, stirring, until slightly thickened, about 3 minutes. Stir in the stock, reduce the heat to low and simmer for 10 minutes. Season with salt.
Light a grill or preheat the oven to 450° and heat a large cast-iron grill pan. Remove the catfish from the marinade and season lightly with salt. If grilling, cook on a lightly oiled grill, turning once, for 4 to 6 minutes per side, or until nicely seared and cooked through. Alternatively, lightly oil the grill pan and cook over moderately high heat until nicely browned, about 3 minutes. Turn the fish and bake in the oven for about 5 minutes, or until cooked through.
Transfer the fish to a serving platter, spoon the sauce over and around the fish and garnish with cilantro. Serve without hesitation.