Heat oven to 350°F. In large skillet, over medium-high heat, sauté zucchini in 1 tbsp margarine 3 minutes or until tender crisp. Remove from skillet; set aside.

In same skillet, prepare RICE-A-RONI^® as package directs using remaining 2 tbsp margarine.

In large bowl, combine prepared RICE-A-RONI, zucchini, cheeses, eggs and pepper. Spoon evenly into lightly greased 2-quart casserole dish. Bake for 25 minutes or until knife inserted 1-inch from center comes out clean.