Peel onions and garlic, chop and mix with mayonnaise. Season with salt and pepper. Pork wash, dry and cut into pieces of 5x5 cm. Put in a bowl, add the prepared mayonnaise marinade, mix thoroughly and leave for 40 minutes.
Remove the pork from the marinade, wipe with napkins. String on 4 skewers and fry on the grill for 20-25 minutes. Serve with ketchup.