Wash and dry the apples well., and remove the heart with a coring tool or by making a cut with a knife around the upper tail, removing the interior little by little with the help of a teaspoon. You only have to remove the hardest and most fibrous part and the seeds, trying not to break the bottom. Sprinkle with a few drops of lemon juice.
Practice a thin cut around each apple, so they do not explode. Fill with frozen blueberries, pressing gently to fit as many berries as possible. Arrange the apples in a microwave-safe bowl or bowl and add a light drizzle of sweetener on top.
Sprinkle with ground cinnamon or other spices, and pour the rest of the juice on top. Put in the microwave, cover with a special lid for this appliance (or cover with plastic film perforated with a fork) and program between 3 and 4 minutes at maximum power.
The final time will depend on the appliance and the size of the apples. If we’re grilling two at a time, we’ll probably need at least the full 4 minutes. They have to be very tender, with the liquefied blueberries and the creamy meat, coming out through the side cut. Remove very carefully.