Potato, leek and bacon pie

Approx 1kg potatoes, peeled and chopped into even sized pieces
3 leeks
1 onion
3-4 slices smoked bacon
bit of garlic

For seasoning the mash -
salt
pepper
lots of grated cheese

Boil the potatoes, and while that's going, sweat off the leeks, bacon and onion with the garlic. When the potatoes are cooked, mash them with the salt and pepper and cheese, and then just layer up in a pie dish and bake at about 180 degrees for about half an hour - 40 minutes.