Saute Beef, Zucchini, Onion, Salt, Garlic Powder And Chili Powder In A Lightly Greased Skillet Until Meat Is No Longer Pink, And Vegetables Are Tender-Crisp. Stir Frequently Add Green Chiles, Rice, Sour Cream And 1 Cup Of The Cheese. Turn Into A Greased Shallow 2 Quart Casserole. Arrange Tomato Slices On Top. Season With Salt And Pepper, And Top With Remaining Cheese. Bake At 350 Degrees 25 To 30 Minutes Or Until Cheese Browns.