1 lg. Spanish onion, 3 c. sliced
3 c. thinly sliced zucchini
1/4 c. butter
2 eggs, beaten
1/4 c. milk
1/2 tsp. slat
1/8 tsp. pepper
1/2 tsp. dry mustard
1 1/2 to 2 c. grated Swiss cheese

Saute onion and zucchini in butter until tender. Put in shallow 1 1/2 quart baking dish. Combine eggs, milk, salt, pepper, mustard, and half of the cheese. Pour over vegetables. Sprinkle remainder of cheese on top. Bake at 375 degrees for 25 minutes or until done. Serves 6.