My mother used to make pierogi quite regularly when I was still living with my parents. I liked pierogis a lot and missed them after I moved out.
One of my hobbies is cooking and trying out historical recipes, so I played around a lot with the ingredients until I found something that suited me. It’s a non-traditional recipe, with a filling based on an old British pasty recipe. In my opinion this is the beauty of pierogi, as you can fill them with whatever you want and tailor them to your particular taste. It is always fun to share food with others as everyone has their own recipes and methods. I’ve discovered a lot of great meals and techniques in this way. The traditional filling is mashed potato and cottage cheese, but you can also make them vegan and fill them with, for example, mushrooms or fruit.
My suggestion would be to experiment with fillings until you find something you like. Additionally, make a large amount of these as it takes about as much time to make ten as it does to make 50. They actually taste better the next day and you can eat them both cold and after being heated in the oven or microwave, and they do not get soggy. They last for a few days in the fridge and do not lose taste if frozen. They also taste great when heated in a frying pan with some butter.