Rinse the scallops in cold water, drain, and pat them thoroughly dry.
Put olive oil and garlic in a small saucepan over medium heat. Stir until the garlic turns a pale gold, then add the scallops. Season with salt and pepper, raise the heat, and cook briskly for a few seconds, stirring often, until the scallops lose their shiny raw look. Turn off the heat.
Preheat the broiler.
Mix in parsley, capers, roasted peppers, and 1 tbsp (15 ml) of the bread crumbs. Divide among the shells or gratin dishes and sprinkle with the remaining bread crumbs.
Broil for about 1 minute, no longer than needed to form a light brown crust. Serve right away.