American Key Lime Pie
["1 Tbsp. (1 envelope) unflavored gelatin", "1/2 c. sugar", "1/4 tsp. salt", "4 egg yolks", "1/2 c. lime juice", "1/4 c. water", "1 tsp. grated lime peel", "few drops of green food coloring", "4 egg whites", "1/2 c. sugar", "1 c. heavy cream, whipped", "9-inch baked pastry shell"]
["Thoroughly mix gelatin, 1/2 cup sugar and salt in saucepan. Beat together egg yolks, lime juice and water; stir into gelatin mixture.", "Cook and stir over medium heat just until mixture comes to boil.", "Remove from heat, stir in grated peel.", "Add food coloring sparingly to tint pale green.", "Chill; stirring occasionally, until mixture mounds slightly when dropped from a spoon."]
["unflavored gelatin", "sugar", "salt", "egg yolks", "lime juice", "water", "lime peel", "drops of green food coloring", "egg whites", "sugar", "heavy cream", "pastry shell"]