Finely chop the cabbage.
Drain the oil from the canned tuna and prepare it.
Mix cabbage, tuna, corn, mayonnaise, salt, and pepper in a bowl.
Heat oil in a pan and spread the mixture in the shape of a pizza.
Top with mozzarella cheese.
Cover with a lid and cook on low heat until the cheese melts.
Cut the finished pizza into bite-sized pieces.