1. Preheat oven to 350.
2. In large skillet over medium high heat saute' zucchini in 1 tbsp margarine or butter for 3 minutes or until tender-crisp.
3. Remove from skillet and set aside.
4. In same skillet, prepare the rice-a-roni according to pkg. directions using remaining 2 tbsp margarine.
5. In large bowl comgine rice mixture, zucchini, cheeses, eggs and pepper.
6. Spoon into lightly greased 2 quart casserole pan.
7. Bake for 25 minutes or until knife inserted in center comes out clean.