* Cut a horizontal slit in one side of each chicken breast half to within 1/2 inches of the opposite side. Spread honey mustard inside each pocket; stuff with two ham slices.
* Place in a greased 13-in. x 9-in. baking dish. Brush with butter; sprinkle with pretzels. Bake, uncovered, at 350° for 40-45 minutes or until a meat thermometer inserted in chicken reads 170°. Yield: 4 servings.