Raspberry, Blueberry, Blackberry, Or Strawberry Filling - cooking recipe

Ingredients

1 1/2 1 1/2 lbs blackberries or 1 1/2 lbs strawberries, sliced
2 teaspoons fresh lemon juice
2/3 cup sugar
2 tablespoons quick-cooking tapioca
1 tablespoon unsalted butter

Preparation

In a small bowl, mash 1 cup berries with lemon juice and 1/3 cup sugar; stir in tapioca and let sit 15 minutes.
In a heavy saucepan, melt butter over medium heat.
Add berry mixture and remaining 1/3 cup sugar and cook, stirring often, until hot, about 3 minutes.
Add remaining berries and bring to a boil, stirring often, cook 3 minutes.
Lower heat, cover, and simmer, stirring often, until tapioca is tender, about 15 minutes; let cool.