In a large bowl, combine the ground beef, rice, tomatoes, tomato sauce,garlic, green onions and seasonings. Set aside.
Thinly slice zucchini and yellow squash lengthwise.
In a 13 x 9 casserole dish, layer beef mixture, zucchini slices and cheese until dish is full, ending with a layer of zucchini and cheese on top. Cover with foil and refrigerate until dinner time or bake immediately at 350 degrees for 40-45 minutes, until bubbly and cheese is melted.