Step 1

Heat oven to 190C/170C fan/gas Heat the oil in a 25cm ovenproof frying pan. Add the onions and cook for 10-15 mins until soft and caramelised. Add the kale and 1 tbsp water, and cook for 5 mins until the kale has wilted. Pour in the balsamic vinegar and bubble for 1 min, then add the eggs. Give everything a quick stir, then leave undisturbed to cook over a low-medium heat for 5 mins until the egg is nearly set and the frittata is turning golden brown on the bottom.

Step 2

Scatter the goat’s cheese over the top of the frittata. Cook in the oven for 10-15 mins until the cheese is bubbling and the frittata is set in the centre.