WARNING...not really diet friendly unless you use ground turkey or really lean ground beef. Low fat cheese would help too.
2 pounds ground beef
1 (10 fluid ounce) A1 steak sauce
2 tablespoons fajita seasoning
2 tablespoons minced onion
8 slices American cheese, divided
2 (4 ounce) cans chopped green chiles, drained
1 (4 ounce) can sliced mushrooms, drained
In a medium bowl, mix together the ground beef, 1/4 cup of the steak sauce, fajita seasoning, and onion until well blended.
Form the mixture into 8 patties. Set aside 4 of the patties. On the other 4 patties, place one slice of cheese, some of the green chilies, and some mushrooms. Place the other 4 patties over the top, press down, and seal the edges so the goodies do not escape.
Grill outdoors or pan fry
Once they begin to brown, brush the tops with remaining steak sauce.
Baste frequently with steak sauce, until meat is no longer pink, and the juices run clear.
You can "stuff" them with whatever you like.