In a large frypan over medium-high heat, melt 40g butter. Cook and stir the garlic and mushrooms in the melted butter for three minutes, being sure to brown the mushrooms a bit. Set aside.
Meanwhile, melt 40g butter in a large saucepan over medium heat. Stir in rice and cook for 1 to 2 minutes. Slowly add vegetable stock 1/2 cup (125ml) at a time, stirring frequently and allowing all the liquid to be absorbed before adding more stock. Continue cooking until the rice is tender to the tooth. Stir in the mushroom mixture and heat through, about 1 minute. Stir in cheese and season with salt and pepper to taste.