1In 3-quart saucepan, mix American cheese, milk, Worcestershire sauce, flour and mustard. Cook over medium-low heat, stirring occasionally, until cheese is melted. Stir in Cheddar cheese until melted. Stir in artichoke hearts and bell peppers.
2Transfer cheese mixture to fondue pot. Keep warm over low flame. To serve, dip bread cubes into fondue.