Citrus Meringue Pie

Directions

1. In a heavy saucepan, combine the egg whites, sugar, water and cream of tartar. Heat over low heat while beating with a portable mixer on low speed for 1 minute, scraping down sides of pan. Continue beating until mixture reaches 160°. Remove from the heat.
2. In a small saucepan, combine cornstarch and cold water until smooth. Bring to a boil; cook and stir for 1-2 minutes or until thickened. Remove from the heat; cool for 1 minute. Whisk into egg white mixture; add vanilla and salt. Beat on high until stiff peaks form. Set meringue aside.
3. For filling, in a large saucepan, combine sugar and cornstarch. Gradually add the grapefruit juice, water, orange juice and lemon juice until smooth. Bring to a boil over medium-high heat; cook and stir for 2 minutes or until thickened. Remove from the heat.
4. In a small bowl, whisk together egg and egg white; gradually stir 1/2 cup hot filling into egg mixture; return all to the pan, stirring constantly. Bring to a gentle boil; cook and stir for 2 minutes. Remove from the heat; stir in grapefruit zest and food coloring if desired. Pour hot filling into crust.
5. Spread meringue evenly over hot filling, sealing edges to crust. Broil for 30-60 seconds or until meringue is golden brown. Cool on a wire rack. Refrigerate for at least 3 hours before serving. Store leftovers in the refrigerator.