Place potatoes and squash on large baking sheet. Toss with oil and garlic; salt and pepper to taste. Bake in a preheated 400°F oven 30 minutes.
Stir in cooked lima beans; continue roasting 10 minutes or until vegetables are tender. Meanwhile, in small skillet over medium heat, toast bread crumbs, stirring frequently (about 5 minutes).
Transfer vegetables to a 2-quart baking dish; toss with half & half and fresh herbs. Sprinkle with bread crumbs; return to oven and continue baking 10-15 minutes or until bubbly.