1 1/2 lb lean ground beef
1/2 teaspoon salt
1/2 teaspoon pepper
2 sweet onions, halved, thinly sliced and separated into half-rings
1/2 cup garlic-and-herbs spreadable cheese
4 Hoagie buns, split
4 leaves green lettuce
Heat gas or charcoal grill (I'm making mine in the skillet). In a medium bowl, mix ground beef, salt and pepper. Shape mixture into 4 oval patties, about 1/2 inch thick, to fit hoagie buns.
Cut 2 (18x12-inch) sheets of heavy-duty foil. Generously spray half of one side of each foil sheet with cooking spray. Place onions evenly in center of sprayed portion of foil; generously spray onions with cooking spray. Fold unsprayed half of foil over onions so edges meet; seal edges, making tight 1/2-inch fold; fold again, allowing space for heat circulation and expansion. Fold other sides to seal.
Place patties and packets on grill. Cover grill; cook over medium heat 11 to 13 minutes, turning patties and packets over once, until meat is done and onions are tender.
Spread cheese onto bottom halves of buns. Top with lettuce leaf, patty and onions. Cover with top halves of buns.
NOTE: I'm skipping all the outside grilling stuff, so I'm doing it all in the skillet, making the patties and when they're cooked, I'm cooking up the onions in the same skillet.