Rhubarb and Blueberry pie ~ ルバーブとブルーベリーのパイ~

As you know, Rhubarb is very sour vegetables when consume as is, and it is suitable for jam and sauce. The recipe I followed used Blueberries putting together with diced Rhubarb.This way the filling became milder in sourness, it actually adds nice and pleasant sweetness.  The recipe also used sour cream for the crust, taking