I served this on top of slices of angel food cake, but this would also be wonderful with pound cake, as a filling for a layer cake, on toast, on ice cream, or with just a plain old spoon.
1 2/3 cup mixed fresh or thawed frozen berries (a mixture of blackberries, raspberries, and blueberries)
3/4 cup granulated sugar
1/2 cup (1 stick) unsalted butter
1 teaspoon grated lemon zest
1 tablespoon lemon juice
4 large egg yolks
1. Combine the berries, sugar, butter, lemon zest, and lemon juice in a saucepan. Cook over low heat, stirring, until the butter is melted and the sugar is dissolved. Simmer for 5 minutes. Blend with an immersion blender until smooth (or transfer to a blender or food processor, if you do not have an immersion blender). Place pan back over low heat for just a minute or two to heat it back up.
2. Lightly beat the egg yolks in a large bowl. Very slowly stream the hot berry mixture into the egg yolks, stirring constantly.
3. Return the mixture to the saucepan, and stir constantly over low heat for 2 minutes. Do not to allow the mixture to boil.
4. Transfer to a container and refrigerate for up to 5 days. It will thicken when cold.
Makes 2 cups