Start by chopping the onion, tomatoes and garlic.
Heat up the olive oil in a large pan and add the chopped onion and garlic. Sauté until they become translucent.
Add the sliced mushrooms to the pan and continue to sauté until they are soft and browned.
Stir in the Arborio rice until it is fully coated with the oil and vegetables.
Slowly add in the vegetable stock, one cup at a time, making sure to stir consistently until each cup of stock is fully absorbed by the rice.
Once all the stock has been absorbed and the rice is tender, add in the chopped tomatoes and stir until well combined.
Season with salt and pepper to taste, and cook for a further few minutes until the tomatoes are soft.
