Preheat a grill to medium-high. In a small bowl, stir together the garlic, olive oil, 3/4 teaspoon salt, 1/4 teaspoon black pepper and the cayenne.
Brush the tomatoes with some of the garlic oil. Grill, covered, turning once, until lightly charred, about 12 minutes; transfer to a plate.
Meanwhile, brush the steak and the rolls with garlic oil. Grill the rolls, turning occasionally, about 2 minutes; grill the steak, turning once, about 4 minutes total for medium-rare. Let the meat rest for 5 minutes, then thinly slice.
Coarsely chop the rolls and tomatoes and toss in a medium bowl; add the rosemary and season with salt and pepper. Divide the steak slices among 4 plates and top with the bread salad.