Place the ProZero, hot water, psyllium husk, yeast and oil into a bowl, mix and leave to stand for 10 minutes.
In a separate mixing bowl, add the Fate All-Purpose Low Protein Mix and slowly add the ProZero mixture, whilst continuously mixing using your hands, to form a dough.
Set aside for 10 minutes to rise.
For the mushroom and pepper filling, place the onion, pepper, mushrooms, basil and oil in a frying pan over a medium heat and cook for 5 minutes or until soft.
Add to a bowl and blend with the hand-held electric blender until smooth.
For the butternut squash and sweet potato filling, boil the butternut squash and sweet potato for 20 minutes or until soft.
Drain and set aside.
In a separate pan, add the garlic, onion and butter and cook for 5 minutes or until soft.
Add to the drained butternut squash and sweet potato to a bowl and blend with the electric hand-held blender until smooth.
To assemble the pierogis place the dough on a clean lightly dusted worksurface and using a rolling pin, roll out to a thickness of 0.5cm.
Using a cutter, cut out 24 circles.
Take each circle into the palm of your hand and fill with 1 heaped tsp of the filling.
Fold the dough over, to form a semicircle and pinch the edges together to seal.
Boil the pierogies in a pan over a medium heat for 2 minutes.
Remove from the pan using a slotted spoon and fry in a pan with butter over a medium heat, for a further 2 minutes on each side or until golden brown.