1 can condensed milk
4 egg yolks, save 1 egg white, reserve the other 3 egg whites
1/2 c. Key lime (or lemon) juice

Beat 1 egg white stiff, fold into above mixture. Beat the 3 egg whites. Gradually add 3 to 6 tablespoons sugar and 1/2 teaspoon cream of tartar. When if forms firm peaks cover the mixture in pie shell and bake at 350 degrees for 15 to 20 minutes until golden brown. Refrigerate for minimum 1 hour. ENJOY!