Chop the onion and mushrooms.
Heat olive oil in a pan, then sauté the onion and mushrooms.
Add the oatmeal to the pan and stir-fry, then pour in the oat milk and bring to a simmer.
Season with salt and pepper to taste.
Stir constantly and cook until the risotto thickens to your desired consistency.
Finish by sprinkling Parmesan cheese on top.