Preheat grill to 350° to 400° (medium-high) heat. Sprinkle fillets with pepper and salt, and let stand 15 minutes. Toss squash, zucchini, and eggplant with 3 Tbsp. Basil-Garlic Vinaigrette.
Grill steaks, covered with grill lid, 5 to 6 minutes on each side or to desired degree of doneness. Remove steaks, and cover with aluminum foil. Let stand 10 minutes.
Meanwhile, grill vegetable mixture, covered with grill lid, 5 to 6 minutes on each side or until tender. Add tomato halves during last 6 minutes of grilling time, and grill 3 minutes on each side or until softened and warm.
Coarsely chop grilled vegetables, and toss together. Cut steak into thin slices. Fan romaine leaves onto a serving platter. Top with grilled vegetables and steak slices; drizzle with desired amount of vinaigrette.
Note: We tested with Organic Girl Romaine Heart Leaves.