Combine the onion, ground beef, veg oil and the dry ingredients into a pan on medium heat.

Chop and boil the potatoes until fork tender and drain the water.

Once the beef mixture has browned, add in the frozen veg and half the butter. Once the mixture has thickened, turn off the heat and cover.

Layer the beef mixture into an oven safe dish, with the potatoes on top. Evenly sprinkle the cheese atop the potatoes. Bake in the oven at 350 until golden brown and serve.