Make the tart base, eliminate any excess air, and chill. Soak the gelatin in water then dissolve it by heating it in the microwave for 20 seconds.
Add the Greek yogurt to a bowl and beat it together with the sugar well with a whisk. Then mix in the lemon juice and gelatin.
Whip the cream until soft peaks form, then mix it into the bowl from Step 2.
Next, fold the jam into the mixture using a rubber spatula until you achieve a marble pattern.
Then, pour the mixture into the baked tarts and leave to chill.
Garnish the completed tarts with fresh blueberries and mint.
You can make 4 mini-cheesecakes if you use some 6 cm ramekins instead.
If you want a denser tart filling then please add the yogurt to some cream cheese. If you add cream cheese then you can get away with not whipping the cream.