How to make
Prepare a blueberry sauce by placing the blueberries with 3.5 oz (100 g) of sugar and a spoonful of lemon juice on the stove over a moderate heat. Boil them for 7 minutes from the moment they start boiling.
Remove the pot from the heat and blend the products briefly, so that there are pieces of blueberries. Allow the sauce to cool.
Whip the cream until it's smooth, without overdoing it, so it does not lump up. Place it in the refrigerator.
Beat the egg whites well, while adding the remaining sugar in portions until the mixture is thick, shiny and fluffy.
Add the blueberry sauce in portions to the egg whites. Stir gently with a silicone spatula, scooping from the bottom until the mixture is homogeneous or with slightly different colors. Try to keep it as fluffy as possible.
Add the cream and mix it in the same way.
Pour the semifreddo mixture into a rectangular cake tin and cover it with cling film, so that its edges protrude out of the tin. Cover the dish tightly with them and store it in the freezer for at least 4 hours.
When the blueberry semifreddo has completely set, remove the cling film gently and turn it over onto a tray.
Garnish it with fresh blueberries and mint leaves and serve it immediately.
Keep in mind that it melts quickly, so take out the whole semifreddo only if you are going to serve all of the portions. Otherwise, you can take out scoops of it, like ice cream and return the rest back into the freezer immediately.
No matter how long this unique dessert stays there, don't worry that it will freeze too much - it will remain fluffy, soft and airy.
Enjoy.