Vinegar Pie - cooking recipe

Ingredients

3 egg yolks
1 c. sugar
1/4 tsp. salt
1 3/4 c. boiling water
1/4 c. cider vinegar
1/4 c. flour or cornstarch
1/4 c. cold water
lemon flavor

Preparation

Dissolve flour in cold water.
Cook in double boiler.
Pour into baked pie shell.
Add egg whites on top.