3 med. zucchini, cut into 1/2" cubes
1/4 c. (1 oz.) shredded, sharp cheddar cheese
1/4 c. (1 oz.) shredded Swiss cheese
1/4 c. sour cream
1 tbsp. butter
1/2 tsp. salt
1/8 tsp. paprika
1 egg yolk, beaten
3 slices bacon, cooked & crumbled
1 tbsp. chopped chives
1/2 c. soft bread crumbs
1 tbsp. butter, melted

Cook squash in small amount of boiling, salted water 5 minutes or until tender; drain well. Place in lightly greased casserole (1 quart); set aside.

Combine next 6 ingredients in small saucepan. Cook over low heat, stirring constantly, until cheese melts. Remove from heat; stir about 1/4 of hot mixture into egg yolk; add back to remaining hot mixture, stirring constantly. Stir in bacon and chives. Pour over squash. Combine bread crumbs and melted butter. Mix well and sprinkle over casserole. Bake at 350 degrees for 25 to 30 minutes. Yield: 4 servings.