Scalloped Vegetable Casserole

Name: Scalloped Vegetable Casserole
Ingredients: 1 tablespoon olive oil; 4 red bliss potatoes, sliced into coins, about 1/4-inch thick; 2 carrots, sliced into 1/4-inch thick coins; 1 large yellow onion, chopped; 1/2 butternut squash, peeled and sliced into half-moons, about 1/4-inch thick; 3 sprigs fresh thyme; 5 tablespoons unsalted butter; Kosher salt and freshly ground black pepper; 1/3 cup all-purpose flour; 1 1/2 cups chicken broth; 1/2 cup milk; 1 cup shredded sharp white Cheddar cheese; 1 1/2 cups panko breadcrumbs