- 4 1-inch-thick slices of crusty bread cut from a wide, round loaf
- Extra-virgin olive oil (EVOO), for liberal drizzling
- 1 garlic clove, smashed and peeled
- 3 8 ounces tuna steaks, cut into large chunks
- 3 sprigs of rosemary, leaves stripped and finely chopped (a couple of tablespoons)
- 1 tablespoon grill seasoning, such as Mccormick Montreal Steak Seasoning
- 1 navel orange, 2 teaspoons of the zest reserved, then peeled and thinly sliced crosswise
- 1 teaspoon Worcestershire sauce
- 2 teaspoons aged balsamic vinegar (eyeball it)
- 4 thick slices of red onion
- 8 thin slices of Fontina cheese (about 4 ounces)
- 2 cups shredded radicchio, arugula or baby spinach
- Salt and freshly ground pepper
Preheat a grill or a grill pan to medium-high. Drizzle the bread with EVOO and grill until toasted, 1 to 2 minutes on each side. Rub the garlic all over.
Place the tuna in a food processor and pulse until ground. Transfer the tuna to a bowl and add the rosemary, grill seasoning, orange zest, Worcestershire sauce and vinegar and a liberal drizzle of EVOO.
Brush the onion slices with EVOO and grill them until tender, 3 to 4 minutes on each side.
While the onions cook, ready the burgers to go on the grill by forming 4 large patties. Grill the patties with the lid down for 2 minutes on each side for rare and up to 5 minutes on each side for well-done. A minute before taking the burgers off the grill, top with an onion slice and 2 slices of cheese. Place the grilled bread on a platter, top with the orange slices, radicchio and burgers. Season with salt and pepper and enjoy!