1. Wash the pork chops and pat dry with paper towels. Season both sides with salt and ground black pepper.
2. Preheat oven to 350 degrees F (175 degrees C).
3. Slice the onion and put the slices on top of the meat.
4. Spoon about 2 teaspoons mayonnaise over the chops.
5. Top each chop with 2 tablespoons grated cheese.
6. Bake in the preheated oven for about 25 minutes.