1. Preheat the oven to 200˚C/180˚C fan/gas mark 6.
2. Melt the butter and olive oil together in a 20cm oven-proof pan. Add the onions and a pinch of salt and cook for about 20 minutes until the onions are golden brown and soft.
3. Add the mushrooms and cook for 5-6 minutes until tender. Add the thyme and season with salt and black pepper.
4. Add the eggs and stir gently to distribute the onions and mushrooms evenly.
5. Cook over a medium-low heat for 4-5 minutes, using a rubber spatula to lift the cooked edges and allow the uncooked eggs to flow underneath, until the outsides of the frittata are just set but the centre is still wobbly.
6. Transfer to the oven and cook for 3-4 minutes, then top with the crumbled goat’s cheese and cook for another 5-6 minutes or until the frittata is set and the cheese is bubbling.
7. Remove from the heat and allow to rest for 4-5 minutes, then transfer to a chopping board and cut into wedges. Serve warm or at room temperature.

Per serving: 353kcals, 27.3g fat (13.2g saturated), 6.4g carbs, 3g sugars, 21.7g protein, 1.9g fibre, 0.3g sodium

Find our tips for cooking frittatas here.