1. Heat the grill to high, or fire up your broiler and set the rack about 4-5 inches from the flames. Grill the bread slices until slightly charred on both sides. Cut into 1-inch cubes.
2. Toss the asparagus with 3 tablespoons of the olive oil. Sprinkle with salt and pepper. Grill or broil for 3 to 5 minutes, until tender. Cut into 1-inch segments.
3. In large bowl, whisk vinegar, garlic, 1/2 teaspoon salt, 1/4 teaspoon black pepper, and the rest of the oil.
4. Add the tomatoes, onion, olives, capers, grilled bread, and the asparagus. Toss well and set aside for 30 minutes before serving.