Feta, Spinach and Caramelised Onion Omelette

method:

• Preheat the oven at 200C/425F/Gas 6. Peel the onions, and then slice them thinly. Melt the butter in an ovenproof pan and add the oil and the onions. Cook over a low to moderate heat until the onions are soft and golden brown.
• Wash the spinach leaves, add to a large pan and place over a moderate heat. Cook until they have wilted, then remove from the pan and carefully squeeze out any excess water and roughly chop them.
• Add the spinach leaves to the cooked onions and crumble over the feta cheese. Break the eggs into a bowl and beat them lightly, adding black pepper and just a touch of salt. Add to the ovenproof pan over a low heat and leave for five minutes, until it is starting to set. Transfer to the oven and bake for a further 2-3 minutes or so until the omelette is just set and slightly runny in the centre.
• Leave to stand for five minutes and serve.