Start by peeling and boiling your large Russet potatoes. Mash them while hot with butter and shredded cheddar cheese. Season with salt and pepper until it tastes very savory. Let the filling cool completely before you use it.

Whisk the gluten-free flour, xanthan gum, and salt together. Add the eggs and sour cream to the dry center. Mix with your hands until a soft ball forms. If it is too dry, add a teaspoon of water.

Dust your clean counter with a little bit of extra flour. Roll the dough out until it is one-eighth inch thick. Use your round cutter to make many small circles. Keep the dough covered so it does not dry out.

Place a small spoonful of potato mix onto each circle. Fold the dough over to create a half-moon shape. Press the edges together very firmly with your fingers. You can use a fork to make a pretty pattern.

Drop the perogies into a pot of boiling salted water. Cook them for about three to five minutes total. They are done when they float to the very top. Remove them with a slotted spoon and drain well.

Melt a large knob of butter in your hot skillet. Add the boiled perogies and the sliced yellow onions. Fry them for two minutes on each side until golden. The skin should look slightly bubbly and very crispy.

Place the hot perogies on a plate with the onions. Add a large dollop of cold sour cream on the side. Serve them immediately while the cheese is still melty. Enjoy your traditional and healthy gluten-free meal!