For romesco sauce
1/3 cup whole blanched almonds, toasted
1 slice firm white sandwich bread, crust discarded and bread torn into pieces
2 large garlic cloves
1/2 teaspoon dried hot red pepper flakes
1/2 cup coarsely chopped drained bottled roasted red peppers
2 tablespoons red-wine vinegar
1/2 teaspoon salt, or to taste
1/4 cup extra-virgin olive oil
4 (6-oz) pieces grouper fillet
1 to 2 tablespoons olive oil
Make sauce: Finely grind almonds, bread, garlic, and red pepper flakes in a food processor. Add roasted peppers, vinegar, and salt, then purée, adding oil in a slow stream. Season with black pepper.
Make fish: Preheat broiler.
Put fish on a lightly oiled shallow (1-inch-deep) baking pan, skin sides down. Brush fish with oil and season with salt and pepper. Broil 3 inches from heat, without turning, until just cooked through, about 7 minutes.