For the Dressing: Whisk the oil garlic, lemon juice, vinegar, mustard, thyme, and salt and pepper to taste in bowl.
For the Salad: Toss zucchini, eggplant, and bell peppers with 3 tablespoons oil in bowl and season with salt and pepper. Brush onion and baguette with remaining 5 tablespoons oil and season with salt and pepper. Grill vegetables and bread until charred on both sides, just 1 or 2 minutes for bread, and up to 12 minutes for onions.
Chop vegetables roughly and toss with pine nuts and 2 tablespoons dressing in bowl. Toss salad greens with 2 tablespoons dressing in second bowl.
Place 3 bread slices on each large plate. Top bread with salad, then vegetable. Drizzle with remaining dressing; garnish with Parmesan. Serve.