Spread 2 teaspoons mustard on 1 bread slice; top with 1/4 cup cheese, 2 tablespoons artichokes, 1/3 cup bell peppers, and 1 bread slice. Repeat procedure with remaining mustard, bread, cheese, artichokes, and bell peppers.

Heat a large nonstick skillet coated with cooking spray over medium heat until hot. Add sandwiches to skillet; cook 2 minutes on each side or until golden brown.