Preheat grill pan to high or preheat grill or charcoal. Coat tuna in balsamic and season with rosemary, salt and pepper. Drizzle fish with oil, coating lightly on both sides, about 2 tablespoons oil, total.
Preheat a medium nonstick skillet over medium high heat. Add 2 tablespoons extra-virgin olive oil, 2 turns of the pan in a slow stream. Add garlic, onion and saute 2 or 3 minutes. Dice the zucchini and squash while the onion begins to soften. Add the zucchini and squash to the pan and turn to coat and combine with garlic and onion.
Slice eggplant into strips and dice, then add to the pan. Turn to combine all of the vegetables. Add thyme, salt and pepper to season the mixture. Cook over medium high heat, stirring frequently, 10 minutes, until vegetables are just fork tender.
Grill tuna 2 to 3 minutes on each side for rare, up to 6 minutes on each side for well done.
When tuna is done and vegetables are fork tender, stir chopped tomatoes into eggplant and zucchini mixture and remove vegetables from heat.
Serve wedges of vegetable antipasto, above recipe, along side tuna steaks topped with vegetable salsa. Extra antipasto slices and vegetables should be passed at the table.
A nice Sicilian rose, chilled, makes a fine beverage companion.
Vegetable Antipasto Stuffed Bread:
1 loaf crusty bread, 9 to 12 inches in length
1/4 cup sun-dried tomatoes in olive oil, drained, chopped -- 1/2 a small jar
1/4 cup black pitted calamata or oil cured olives, your preference, chopped
1/2 cup prepared pesto sauce
1/4 pound deli sliced provolone
1 jar, 16 to 18 roasted red peppers, drained
1 (15-ounce) can quartered artichoke hearts in water, drained
1 cup giardiniera, pickled vegetables (hot pickled peppers, cauliflower, carrots available on the Italian foods aisle of market or in bulk bins near deli section with bulk olives)
Coarse salt and black pepper
Extra-virgin olive oil, for drizzling
Cut the top off a loaf of crusty bread. Hollow out the inside of the bread.
Mix parsley, chopped sun-dried tomatoes, chopped olives and store bought or homemade pesto sauce. Spread the mixture evenly across the bottom of the hollowed out bread. Layer the cheese into the loaf. Layer the roasted red peppers on top of the cheese. Coarsely chop the drained artichoke hearts and add them in a layer over the red peppers. Sprinkle in the chopped hot pickled vegetables and drizzle some extra-virgin olive oil on top. Replace the top, cut the stuffed loaf into pieces and serve.