3 medium onions, halved and thinly sliced
1 tbsp brown sugar
1 tbsp balsamic vinegar
1 tbsp thyme leaves
4 tbsp extra virgin olive oil
450-500g potatoes, peeled (I used Rooster)
6 free-range eggs, lightly whisked
150ml double cream or Greek Yogurt
1 tsp dijon mustard
100g Gorgonzola cheese
A green salad, to serve
Heat the butter in a wide frying pan until foaming. Add the onions and reduce the heat. Sauté until melted, stirring occasionally. This will take about ten minutes. Add the brown sugar, balsamic vinegar and thyme leaves. Heat for a further five minutes and then transfer to a bowl.
Whilst the onions are cooking boil the potatoes until just tender but still firm. Drain and leave to cool slightly. Next slice the potatoes into thick rounds.
Heat the olive oil in a large non stick frying pan. Arrange the potato slices on the base. Top with the caramelised onions and any remaining potato. Whisk the eggs with the mustard and cream. Pour the mixture over the potatoes and lower the heat to a minimum. Leave to cook for ten to twelve minutes or until the base is set. Crumble the gorgonzola over the top.
Preheat the grill to high and place the frittata underneath for five minutes or so to finish cooking. It should be golden brown and just set. Leave to settle for five minutes before turning out onto a serving plate. Cut into wedges and serve warm or at room temperature with salads.