Prepare as directed, substituting a 4-oz. boneless skinless chicken breast for each steak and increasing the grilling time to 3 to 4 min. on each side or until chicken is done (165ºF).
Instead of cooking in the panini grill, place assembled sandwiches on preheated 350ºF-flat-top griddle. Cover with weight. Cook 2 min. on each side or until sandwich is golden brown on both sides and cheese is melted.
Open-Face Flatbread Steak Sandwich
To serve as open-face sandwich, assemble sandwich as directed except do not top with the second flatbread. Place in sheet pan. Bake in 350ºF-convection oven 2 to 3 min. or until cheese is melted and all ingredients are heated through.