The slices of pork tenderloin must be smaller and, above all, thin so that you can roll them up with the feta cheese, which is cut into wider strips, and stick them on skewers.
First season the meat to taste with salt, herbs, pepper and possibly a little garlic. Then roll up the cheese in the meat slices.
Peel and quarter the small onions. Clean the mushrooms and cut into thicker slices (other vegetables can also be used depending on your taste).
Then stick the meat rolls alternately with the onion pieces and the mushroom slices on skewers.
Place the skewers on a grill tray and roast on the grill until they are nicely browned.