Steps

1. To roast or broil: Preheat the oven to 400 degrees. Put the peppers in a foil-lined roasting pan, then roast or broil, turning the peppers as each side browns until they have darkened and collapsed. The process takes 15 or 20 minutes in the broiler, or up to an hour in the oven.
2. To grill: Heat a grill and put the rack about 4 inches from the heat source. Put the peppers directly over the heat. Grill, turning as each side blackens, until they collapse, about 15 minutes.
3. Wrap the cooked peppers in foil (if you roasted the peppers, use the same foil that lined the pan) and cool them enough to handle. Remove the skins, seeds, and stems (this process is sometimes easier under running water). Don’t worry if the peppers fall apart.
4. Serve at room temperature (even if they’ve been refrigerated), sprinkled with a little salt and olive oil. Store in the refrigerator.
5. To make the sauce: Put the roasted red peppers in a food processor or blender with a few drops of olive oil, stock, white wine, or water — just enough to get the machine working. Sprinkle with salt and pepper, if desired. Add one or more of the optional flavorings, if desired. Blend into a smooth purée.