Step 1.  Place cauliflower, cream, and butter in a microwave-safe bowl and cook for 6 minutes on High. Stir to make sure that all of the florets are covered in cream and then cook for another 6 minutes.

Step 2.  Transfer to a blender or food processor and add in the cheese. Process until the mixture is fully blended and smooth. Salt and pepper to taste. Set aside.

Step 3.  Microwave the butter and mozzarella cheese for the dough on High for 1 minute. Stir and cook for one minute more. Stir well to combine.

Step 4.  Allow the cheese to cool for 2 minutes and then mix in the egg and egg yolk. Mix until smooth.

Step 5.  Mix in the almond flour to form a soft dough. Knead a few times to make sure that the dough is fully blended.

Step 6.  Place the dough between 2 pieces of parchment or wax paper. Roll out the dough until it is quite thin, about 1/8 of an inch. Use a circle cookie cutter or a glass to cut 3 1/2" circles out of the dough.

Step 7.  Drop a tablespoon of filling on each circle of dough. Carefully fold the dough in half and seal the edges by pressing down with your fingers.

Step 8.  Melt the remaining 1/2 a stick of butter in a large skillet over medium heat. Cook the shallots for a few minutes until they have softened. Add the pierogies in batches and cook until browned on both sides.

Step 9.  Serve the pierogies with onions on top and a side of sour cream.