Raspberries and blueberries selected. Wash raspberries if necessary, wash blueberries and strawberries. Clean and quarter the strawberries. Mix the berries and 2-3 tbsp. sugar and place in a flat casserole dish.
Preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer).
Separate eggs. First beat the egg whites and 1 pinch of salt, then 100 g cream until stiff. Beat the egg yolks, cardamom and 75 g sugar for 5-6 minutes until light creamy. First fold 1⁄4 egg whites, then cream and the rest of the egg whites into the egg yolk mixture.
Spread on the berries. Bake in a hot oven for 20-25 minutes until golden brown.
Remove the berry gratin and dust with icing sugar. Whip 100 g cream until semi-stiff, serve with hot or lukewarm gratin.