Joe Swash’s mushroom risotto

1tbsp olive oil

50g butter

1 small onion or shallot, finely chopped

1 leek, finely chopped

300g mushrooms (white/button/cremini/chestnut), finely chopped

4 garlic cloves, very finely chopped

1 large sprig of thyme, leaves picked

400g risotto rice

100ml white wine or Vermouth

1.5L chicken or mushroom stock

50g Parmesan, grated, plus extra to serve

Salt and black pepper

To garnish:

15g butter

250g mixed mushrooms, sliced if large

2 garlic cloves, crushed or finely chopped