The fat part is in the sauce here.
Cut some bacon into about 1″ pieces and fry until it’s the way you like it. Drain what you can of the grease and put bacon aside.
Start water boiling for perogies.
Add about 1/2 an onion diced and a heaping tablespoon of butter with some garlic salt or powder back into your frying pan.
Cook until onions are clear.
Pour 1/2 can sweetened condensed milk and 1/2 can evaporated milk into pan.
Add bacon back in and cook for about 5 min until it’s all combined.