Cut potatoes into bite-sized pieces and soak in water briefly, then drain. Mince the onion.

In a frying pan, add breadcrumbs and salad oil. Stir-fry over medium heat until golden brown, then set aside.

Using the same pan, sauté ground meat and onion over medium heat. Add salt and pepper to season.

Place potatoes in a microwave-safe container, cover loosely with plastic wrap, and microwave at 600W for 4 minutes.

Mash the hot potatoes, then mix in cheese, butter, the sautéed meat mixture, and milk. Stir well and microwave at 600W for 1 minute.