I find it helpful to cook the blueberry portion just a little longer after the whole berries are added to make sure the topping is thick enough.

1 9 inch deep dish pie crust, baked
For the lemon filling:
1/4 cup corn starch
1 cup sugar
1/4 cup fresh lemon juice
4 extra large egg yolks
1 1/4 cup water
1 tsp grated lemon zest
1 Tbs butter
For the blueberry filling:
3 cups fresh or frozen blueberries
1/2 tsp grated lemon zest
1/8 cup fresh lemon juice
1 tsp quick-cooking tapioca
2 Tbs sugar
For the meringue:
4 extra large egg whites, room temperature
6 Tbs sugar

1. For the lemon filling: In a medium saucepan, combine the corn starch, sugar, and lemon juice and mix well. Beat the egg yolks and add to the cornstarch mixture. Gradually add the water. Bring the the mixture to just boiling over medium high heat and simmer gently for 5 minutes, stirring constantly. Remove from the heat. Add butter and grated lemon rind to the thickened mixture and stir until thoroughly blended. Pour into the prepared crust.
2. For the blueberry filling: In 1-quart saucepan, mix 1 cup of the blueberries, the lemon peel, lemon juice, tapioca and 2 tablespoons sugar. Using potato masher or fork, mash blueberry mixture well. Cook over medium-low heat about 15 minutes, stirring constantly, until thickened. Stir in the remaining 2 cups blueberries. Spread the filling evenly over the top of the cooled pie.
3. For the meringue: Preheat the oven to 400°. With an electric mixture at high speed, beat the egg whites until soft peaks form. Gradually add the sugar. Continue to beat on high speed to form stiff, glossy peaks. Spread the meringue over the filling, carefully sealing the entire edge of crust to prevent shrinking. Bake for 8 to 10 minutes until golden. Cool on a cake rack away from draft for 2 hours. Refrigerate and serve cold.

Servings: 8