In same saucepan, melt butter over medium-high heat. Cook bell pepper, shallots and garlic in butter, stirring frequently, until bell pepper is crisp-tender. Stir in flour and pepper. Cook over medium heat, stirring constantly, until mixture is bubbly; remove from heat. Stir in milk. Heat to boiling, stirring constantly. Boil and stir 1 minute; remove from heat.