In a large plastic bowl add the ground beef, garlic, scallions, onion, cumin, salt and pepper. Mix well and refrigerate for about 1 hour. Form 4 patties.
Heat a grill or sautué pan and cook the hamburgers for 5 minutes on each side until done. Remove to a plate and cover with aluminum foil.
Spray a large grill pan, (or even your outdoor grill) with cooking spray and heat over a medium flame. Grill the pineapple for 2 to 3 minutes on each side, until it is nicely brown and grill marks have appeared.
Allow the hamburgers to rest for 5 minutes and serve immediately on buns with the 1 pineapple slice, 1 ham slice and 1 cheese slice.