Prepare a single pie crust

Preheat oven to 400°F / 205°C

For filling

1. Combine lemon juice and the zests
2. Stir in the eggs, egg yolks and sugar
3. Cook and stir over medium heat until mixture thickens slightly and comes to gentle boil
4. Cook and stir for 2 minutes more
5. Remove from heat and whisk in butter a little at a time until melted
6. Pour filling into baked pie shell
7. Cover with plastic wrap and set aside while preparing meringue

For meringue

1. Place egg whites and cream of tartar in mixer bowl
2. Whip on high speed until soft peaks form - set aside
3. Combine sugar and water in a saucepan - bring to a boil
4. Cook until mixture reaches 235°F, usually about 5 minutes
5. With mixer on medium speed, slowly drizzle hot syrup into egg whites - continue until stiff peaks form
6. Immediately spread over filling, carefully sealing to edge of pastry
7. Bake for 9 to 12 minutes, or until lightly browned
8. Cool for at least 1 hour. Chill 3 to 6 hours