Here's a recipe I have to try - possibly with some additions of my own:
Stilton, onion and potato pie
by Nigel Slater
from The Kitchen Diaries
Preparation time less than 30 mins
Cooking time 1 to 2 hours
1.5kg/3lb 5oz floury potatoes, quartered
4 medium onions, halved and cut into 5 or 6 segments
150ml/5fl oz milk
freshly ground black pepper
25g/1oz grated parmesan
Put a large pan of water on to boil. Peel the potatoes and cut them into halves or quarters, then add them to the boiling water. When it comes back to the boil, add a little salt and turn down to a lively simmer. Check the potatoes now and again; they should be tender in fifteen minutes or so.
Whilst the potatoes cook, peel the onions and cut them in half, then cut each into five or six segments. Put them into a heavy-based frying pan with 40g of the butter and let them cook over a moderate to low heat, stirring from time to time. They will need twenty to twenty-five minutes to become thoroughly soft and sticky.
Bring the milk to the boil and turn off the heat. Drain the potatoes, then tip them into the bowl of a food mixer fitted with a beater attachment. Mix as you slowly add the milk and the remaining butter. Beat to a smooth mash, stopping well before it becomes gluey.
Set the oven at 200C/400F/Gas 6. Butter the base and sides of a heavy 28cm/11in frying pan with a metal handle or a similar diameter baking dish - I use a black, cast-iron frying pan. Spoon in half the mashed potato, smooth the potato a little, then add the onions and a grinding of black pepper. Crumble the Stilton over the onions. Pile the rest of the mashed potato over the top and smooth lightly with the back of the spoon or a rubber spatula.
Dust over the grated Parmesan, then bake for twenty-five to thirty minutes, by which time the top will be pale gold and the filling will be bubbling up around the edges.
Notice, if you will, the clever usage of a rubber spatula, Lord Ellpus.