Peel and chop the onion. Melt the butter in a large casserole dish over a medium heat, add 2 tablespoons of the olive oil and tip in the onion. Stir and sizzle for 2 minutes.
Roughly slice the mushrooms and add to the dish. Cook for 5 more minutes, until the mushrooms have reduced in size. Add the rice and stir well.
Pour in the Madeira, stir and allow to reduce down. Begin adding the stock, a little at a time, stirring until the rice has absorbed the stock before adding more. Continue until all of the stock has been used and the rice is plump and tender.
Stir in the thyme, then turn off the heat. Add the remaining olive oil and the parmesan to the risotto (don’t stir it) and put the lid on the dish. Leave for 5 minutes, then stir well and serve.
Notes
Easy Variations
One of the nicest things about risotto is how adaptable it is.Add greens - Spinach or peas stirred in at the end add colour and freshness.Make it extra mushroomy - Add a few dried porcini mushrooms (soaked in hot water first) for an even deeper flavour.Make it vegan - Simply omit the butter and parmesan or replace them with vegan alternatives.
Storage and Reheating
Risotto is best eaten fresh, but leftovers can still be very enjoyable.Store in an airtight container in the fridge for up to four days.When reheating, add a splash of water or stock and warm gently on the hob or in the microwave until hot.