Slice the leek into rounds and chop the bacon into bite-sized pieces.

Heat salad oil in a frying pan over medium heat and sauté the leek until softened. Add the bacon and cook until slightly crispy.

In a bowl, whisk the egg and mix in milk, mayonnaise, and salt and pepper.

Place dumpling wrappers into aluminum cups and fill with the sautéed leek and bacon mixture. Top with shredded pizza cheese.