In a small bowl, blend sugar and flour well. In a heavy-bottomed saucepan, mix sour cream with egg yolks, sugar mixture and dried blueberries, blending well with each addition. Over medium heat, bring to a bubble and cook for about 5 minutes, stirring frequently as the mixture thickens to aid even cooking and prevent scorching. Set aside.

Preheat oven to 400°. For the meringue, place egg whites and cream of tartar in a large bowl and whip. Once soft peaks start forming, add sugar gradually while whipping, until all sugar has been used and egg whites are thick and glossy and hold their shape.

Pour the slightly cooled filling into pie shell. Mound meringue mix evenly on top, bringing it to the edges and making sure it seals well with the crust. Using a spatula, make peaks all around the meringue. Bake in preheated oven for 15–20 minutes, watching closely; remove pie when peaks are golden brown. Cool before serving, but do not refrigerate unless keeping overnight.