Coat a food rack with vegetable cooking spray; place on grill over medium-high heat (350° to 400°). Place chicken on rack; brush with half of mustard mixture. Grill 5 minutes; turn chicken, and brush with remaining mustard mixture. Grill 5 more minutes or until done. Garnish, if desired.
Note: To bake chicken, place in a lightly greased 11- x 7-inch baking dish, and brush with mustard mixture. Bake at 375° for 15 minutes or until done. Broil 4 inches from heat (with electric oven door partially open) 1 to 2 minutes or until golden.