In a grill with a cover, prepare a medium-hot fire for direct-heat cooking.

In a small bowl, mix together the mayonnaise and basil. Set aside. In another small bowl, combine the feta cheese and tomatoes. Divide into 6 equal portions, forming balls. Set aside. In a large bowl, combine the ground sirloin, eggs, pepper sauce, Italian seasoning, salt, pepper, garlic, bread crumbs, and Parmesan. With hands or a large spoon, gently bring all ingredients together; do not overmix. Form meat mixture into 12 patties. On 6 of the patties, gently place the feta and tomato mixture onto patties, pressing down lightly. Place remaining patties on top, press, and seal edges to totally enclose filling, forming 6 total patties.

When the fire is ready, brush the grill rack with vegetable oil. Place patties on grill, cover, and cook for 4 minutes, until bottom is brown. With spatula, turn over patties and cook an additional 4 minutes, or until done to your preference. During the last few minutes of grilling, place focaccia, cut side down, on outer edges of grill to lightly toast.

Spread generous portions of basil mayonnaise on cut sides of bread. Place patties on bottom pieces of bread, then top with a slice of prosciutto, a lettuce leaf, and red onion rings. Top with remaining bread and serve.

A viewer, who may not be a professional cook, provided this recipe. The Food Network Kitchens chefs have not tested this recipe and therefore, we cannot make representation as to the results.