_6 servings_
1 package (10 ounces) frozen chopped spinach
1 tablespoon finely chopped onion
¼ cup fat or oil
⅓ cup flour
1½ cups milk
1½ teaspoons salt
¼ teaspoon pepper
4 eggs, separated
½ teaspoon cream of tartar
Cook spinach as directed on package, but omit salt. Drain.
Lightly brown onion in fat in a heavy 1-quart saucepan. Blend in flour.
Slowly stir in milk. Bring to a boil, stirring constantly. Reduce heat
and cook 1 minute more, stirring constantly. Add salt, pepper, and
spinach.
Beat egg yolks slightly; stir in a little of hot mixture. Then stir egg
yolks into remaining hot mixture and cook 1 minute more. Cool slightly.
Add cream of tartar to egg whites and beat until stiff but not dry.
Fold in spinach mixture. Pour into a greased 2-quart casserole. Set
casserole in a pan of hot water.
Bake at 350° F. (moderate oven) about 1¼ hours. Souffle is done when a
knife inserted in the center comes out clean.