2 tblsp donegal rapeseed oil 25g (1oz) unsalted butter 3 Spanish onions, thinly sliced 6 rindless smoked bacon rashers, cut into small lardons 2 garlic cloves, crushed 1 tsp fresh thyme leaves 8 large eggs, lightly beaten 50g (2oz) freshly grated Parmesan 1 tsp finely chopped fresh sage 1 tblsp chopped fresh flat-leaf parsley Lightly dressed salad leaves, to serve Sea salt and freshly ground black pepper
Heat 1 tablespoon of oil and all the butter in a large sauté or frying pan. Add the onions and start by cooking over a fairly high heat, stirring constantly until they begin to soften but not brown.
Reduce the heat and continue to cook over a medium heat, stirring frequently so the onions don’t stick or colour. They will need about 30 minutes in total to caramelise.
Stir the bacon into the onions with the garlic and thyme 5 minutes before the end of the cooking time and continue to cook until the bacon has begun to sizzle and crisp up. Tip into a large bowl and leave to cool.
Preheat the oven to 180°C (350°F/gas mark 4).
Add the eggs, Parmesan, sage and some salt and pepper to the onion and bacon mixture and stir well to combine.
Heat 1 tablespoon of oil in an ovenproof heavy-based pan that’s about 20cm (8in) in diameter and deep enough to take the mixture. Swirl to coat the sides of the pan evenly with the oil, then pour in the egg mixture and cook for 6-8 minutes over a low heat to set the bottom and sides.
Transfer the pan to the oven and cook, uncovered, for about 20 minutes, until just set, puffed up and lightly golden. Remove from the oven and leave to settle for 5 minutes.
To serve, scatter over the parsley, then loosen the sides with a palette knife and cut the frittata into wedges. Serve warm or cold onto serving plates, straight from the pan. Have a bowl of salad leaves on the table so that everyone can help themselves.