In an oven-proof pot or deep pan/skillet, sauté the onion and fresh garlic in a tablespoon of butter until soft and translucent.
Add the rice then pour in the stock and cream. Season generously with salt and pepper.
Cover and place in a preheated oven for 15 minutes.
Remove from the oven and stir vigorously. Taste and if the rice needs more cooking, add another half cup to cup of stock and place back in the oven to bake for another 5-10 minutes.
Remove from the oven and stir in the butter and parmesan then season to taste, if necessary.
While the risotto cooks, melt the butter in a large skillet and add the mushrooms.
Cook for a few minutes until golden brown then add the garlic and thyme.
Allow to cook for another minute or two then add a generous squeeze of lemon juice and season with salt and pepper.
Serve the creamy risotto topped with the mushrooms and grate over more parmesan.