Mince the onion.

In a skillet, add mayonnaise and breadcrumbs. Toast over medium-low heat until golden brown, then set aside.

Cut the potatoes into bite-sized pieces. Boil them in a pot of water over medium heat for about 10 minutes until soft. Drain the water, return the potatoes to the pot, and heat over medium heat until dry. Mash the potatoes in a bowl.

Heat vegetable oil in a skillet. Add ground meat and minced onion, and sauté over medium-low heat for 4-5 minutes. Season with salt and pepper, then mix in the mashed potatoes until evenly combined. Flatten the mixture in the skillet and sprinkle with the toasted breadcrumbs.