Peel 1 large sweet red pepper by burning off the skin on a grill, in the flame of a gas stove, or under a broiler. Remove the seeds from the pepper, coarsely chop the pulp, and put it into a saucepan with 2 cups (500 milliliters) of concentrated white stock. Slowly simmer the chopped red pepper in the stock for 10 minutes. Add ½ cup (125 milliliters) of heavy cream to the mixture and reduce the mixture if necessary to the desired consistency. Finish the sauce with 8 ounces (250 grams) of butter. Season the sauce and strain it through a fine chinois. A small pinch of cayenne pepper or a few drops of hot pepper sauce will help wake up the flavor of this sauce. Some chefs prefer making this sauce with Sweet Pepper Purée), which gives it more color and a more assertive taste.