Preheat oven to 475°. Toss together cauliflower, mushrooms, 2 1/2 Tbsp. oil, 1/2 tsp. cumin, 1/2 tsp. salt, and 1/8 tsp. pepper in a medium bowl. Spread cauliflower mixture in a single layer in jelly-roll pan.
Toss together sweet potatoes, 2 1/2 Tbsp. oil, and remaining cumin, salt, and pepper. Spread in a single layer in another jelly-roll pan.
Bake potatoes and cauliflower at 475° for 10 to 12 minutes or until browned and just tender, turning once. Cool on wire racks 10 minutes.
Reduce oven temperature to 375°. Heat remaining 1 Tbsp. oil in a large skillet over medium-high heat. Add garlic; cook, stirring often, 1 minute. Add kale; cook, stirring occasionally, 10 minutes or until tender. Add salt and pepper to taste; stir in vinegar.
Layer half each of sweet potatoes, cauliflower mixture, beans (if desired), kale, and 1 1/2 cups Easy Cheese Sauce in a lightly greased 13- x 9-inch baking dish. Repeat layers once. Top with remaining 1/2 cup cheese sauce. Stir together panko, chopped cilantro, and olive oil, and sprinkle crumb mixture over casserole.
Bake at 375° for 20 to 25 minutes or until thoroughly heated, bubbly, and golden brown. Let stand 5 minutes before serving.