Preferably, make the tart shells a day before.

Cream butter and sugar until pale and fluffy. Add in egg.

Sift flour in in two batches until the butter mixture firms up. Knead into dough and chill in refrigerator until workable.

Separate dough into portions and press evenly intp tart moulds. Alternately, roll out the dough and cut out circles with a cookie cutter and press into tart moulds.

Bake in preheated oven for 10-15 minutes or until golden at 200℃. Chill in fridge for a couple of hours, preferably overnight.

Meanwhile, cream the cream cheese, butter and sugar until creamy.

Add in egg and beat until incorporated. Stir in the whipping cream.

Sift in the flour to thicken the mixture. Alternate whipping cream and flour if the mixture gets too thick or watery.

Spoon the cream cheese filling into the tart shells. It will rise slightly in the oven, so fill halfway will do.

Drop teaspoons (or more!) of blueberry jam onto the middle of the filling and swirl with a chopstick (toothpick) to achieve a marbled look.

Bake in preheated oven at 150℃ for ten minutes or less until the surface of the filling is firm but not dry.

Serve chilled.