I used normal cheese (we did Gouda and it was delicious) and didn’t do mushrooms since I didn’t have any and also added carrots. Everyone loved it! I do recommend baking it in the oven after frying. It also took me a little longer than the recipe said and was rather labor intensive. Good though. Next time I make it I’ll add extra slices to the potato dough and maybe mix in some shredded cheese with the mashed potatoes before filling them with the veggies!