Heat oven to 350°. Cut bread into 1-inch cubes. Place bread pieces in ungreased jelly roll pan, 15 1/2x10 1/2x1 inch. Bake about 10 minutes, stirring twice, until lightly toasted. Transfer to serving bowl or basket.
Meanwhile, melt cheese in 2-quart saucepan over medium heat, stirring occasionally. Stir in broccoli, beer, pimientos and mustard. Cook, stirring occasionally, until hot. Pour cheese mixture into ceramic fondue pot over Low heat or into 1 1/2-quart slow cooker at Low heat setting.
To serve, skewer toasted bread pieces with fondue forks or wooden skewers and dip into cheese mixture. Cheese mixture will hold in slow cooker on Low heat setting up to 2 hours. 16 servings (1/2 cup bread cubes and 2 tablespoons fondue