Ingredients (Serves 4)
Preheat the oven to 160°C, 300°F, Gas 2 and grease and line a 900g/2lb loaf tin or round cake tin if you prefer wedges to slices.
Melt the butter in a heavy-bottomed frying pan, add the potato and pancetta and cook over a medium heat for about 4 minutes. Add the onion and cook until starting to colour and soften. Season well with salt and freshly ground black pepper. Beat the eggs with the chives and double cream, then stir in the grated cheese.
Scatter the prepared tin with the potato mixture and the avocado, pour over the egg mix, transfer to the oven and bake for 25-30 minutes or until set then serve straight away.