Step 1

Take a small bowl, add the water and arrowroot. Stir to combine until no lumps are visible set it aside

Step 2

Now take a medium saucepan and add the frozen berries, sugar, lemon juice, and the arrowroot water mixture

Step 3

Put the pan on a medium-hot stove and stir the berries regularly so the berries thaw and the arrowroot dissolves

Step 4

The berries get shiny and break apart a little bit. Let the sauce simmer so it can thicken

Step 5

This takes about 5 minutes. If the sauce is too thick you can add some additional water

Step 6

When you have a thick, jam-like sauce take the pan off the stove and let it cool

Step 7

Your filling is ready for use