This was an easy one. I used fresh blue berries and a few strawberries. I´m sure you can use frozen as well since it is a gratin.
I used a 9 inch baking dish since I do not have gratin dishes for 5 people only 3.
I served this dish warm and the verdict was: “This is like eating warm jam”. I served it the day after cold and still the verdict was this is like jam. I liked it, but will not be making it again.