Alec- Is this what you want?

Pan Haggerty

450g (1lb) Potatoes
110g (4oz) Cheddar or Lancashire Cheese
2 medium Onions
25g (1oz) Butter
1 tbsp Vegetable Oil
Salt and Pepper

Thinly slice the potatoes and onions and grate the cheese.
Combine the butter and oil in a large frying pan.
Remove the pan from the heat and place layers of sliced potatoes, onions and cheese, reserving a little of the cheese.
Cover and cook gently for about 30 minutes or until the potatoes and onions are cooked.
Pre-heat the grill five minutes before the end of the cooking time.
Sprinkle the reserved cheese over the top of the mixture, place under grill until the cheese is golden brown and bubbling.
Serve straight from the pan.

I'll post a link to the source in a moment...