1Heat oven to 425°F. Fold small sheet of heavy-duty foil in half, creasing it to form double thickness. Place garlic in center of foil; drizzle with 1 teaspoon water. Fold foil tightly to seal. Bake 20 minutes or until garlic is lightly browned and tender. Transfer garlic to small bowl; mash with fork.
2Increase oven temperature to 450°F. Spray cast-iron skillet or small shallow roasting pan with cooking spray. In skillet or pan, toss broccoli with oil and roasted garlic. Spread broccoli in single layer.
3Roast uncovered 10 minutes or until broccoli begins to brown. Stir in tomatoes, butter, salt and pepper. Roast 12 minutes longer or until tomato skins begin to split.