1/4 c. melted butter
1/2 c. flour
3 egg yolks
1 1/2 c. milk
1/4 c. lemon juice
1 tsp. lemon extract

Blend all ingredients for 5 minutes. Beat leftover egg whites until stiff. Add to first mixture. Bake in well greased casserole for 45 minutes in pan of hot water until knife comes clean from center.