Italian Potato Salad

Combine oil, garlic and lemon zest in a measuring cup; set aside. Arrange potatoes in a steamer basket. Add carrots and steam for 8 minutes. Add beans, zucchini and summer squash, and steam just until tender-crisp, 3 to 5 minutes longer. Do not overcook. Lift out steamer and transfer vegetables to a large bowl.

Add scallions and splash vegetables with 2 tablespoons of the vinegar mixture. Toss gently, and let sit until cooled, about 15 minutes. Combine remaining vinegar mixture with oil mixture and drizzle over salad. Season with salt and pepper and serve on lettuce leaves.