This recipe creates a hearty pierogi casserole by layering homemade dough with creamy mashed potatoes, crispy bacon, sweet caramelized onions, and a blend of Gruyere and farmer's cheese. The dish requires careful preparation of each component before assembly and baking, resulting in a comforting, golden-brown casserole that's perfect for a substantial meal.
For the dough, avoid overworking it; a slightly shaggy dough is desirable for tender pierogi. The long chilling time is crucial for gluten relaxation, making the dough easier to roll. When mashing potatoes, incorporate hot cream and cold butter slowly for the smoothest, richest texture, akin to a potato puree. Salt the potato water generously for flavor from within. Take your time caramelizing the onions—low heat and patience yield a deep, sweet flavor that's essential for balance. Ensure your bacon is truly crisp before adding to the layers for textural contrast. Lastly, letting the casserole rest after baking allows the layers to set, preventing it from falling apart when served.