
Ingredients
- 2 tbsp of olive oil
- 1 red onion, sliced
- 450 g of leftover roast potatoes
- 1 tbsp of rosemary, finely chopped
- 400 ml of leftover gravy
- 175 g of gruyère, thinly sliced
Method
Step 1
Preheat the oven to 200°C/180°C fan/gas 6. Add the olive oil to a small frying pan over a medium heat and fry the onion for about 10 mins, until just soft and beginning to caramelise. Set aside.Step 2
Meanwhile, put the potatoes into a baking dish, season with salt and pepper and the rosemary, then put in the oven for about 15 mins to reheat. When the potatoes are nearly done, reheat the gravy in the microwave or on the hob.Step 3
When the potatoes are hot, remove from the oven, scatter over the onion, and add the cheese in an even layer. Pour over the hot gravy and return to the oven for 5 mins, until the cheese melts. When plating up, sprinkle over some black pepper and any toasty rosemary that’s left in the baking dish.