Grind. Strain the resulting berry puree through a sieve.
In a saucepan, mix the egg with the sugar.
Add the milk and sift the flour. Stir well. Put on a small fire. Continuously stir the mass to avoid the formation of flour lumps. As soon as the custard thickens and begins to boil, remove from the stove.
Allow the cream to cool slightly and add the cranberry puree.
Stir. The sauce is ready.
This sauce is perfect for cheesecakes, pancakes, pancakes.