To serve: Parmesan shavings, micro herbs and lemon zest
Keep mushroom stock warm in a pot on the stove.
For the risotto base:
Heat olive oil and butter in a large pot. Add onion and a pinch of salt and cook until the onion is very soft. Add the garlic and chilli flakes and cook until fragrant.
Add rice and stir well. Toast the rice until the grains are translucent around the edges and beginning to brown. Add wine and stir until wine is completely absorbed.
Reduce heat to medium low, and ladle in hot mushroom stock stirring constantly and allowing liquid to absorb fully before adding more. Keep adding stock until rice is creamy but remains al dente. Adjust seasoning.
Switch off the heat. Stir through the lemon zest. Add the final butter and parmesan. Stir quickly and then place the lid on the pot and leave until serving.
For the mushrooms:
Heat oil in a large frying pan. Add mushrooms and season with salt and pepper. Cook, tossing occasionally, until golden browned and tender.
Add thyme, garlic, and butter and cook until garlic softens and butter is golden brown. Remove from heat and add lemon juice. Toss to coat and discard the thyme sprigs.
Divide risotto among bowls. Top each with a few spoonfuls of mushroom mixture. Serve with micro herbs, an extra grating of lemon zest and Parmesan.