In a sauté pan, heat the olive oil or thoroughly cover with cooking spray. When the pan is hot, toss in the onions and cook until golden and fragrant, about 2 minutes. Add in the mushrooms and thyme, making sure to space them out in the pan so the mushrooms have room to brown. When everything is a deep bronze colour and most of the oil is gone, turn off the heat and transfer to a plate.

In the same pan, heat the oats dry, over low heat, so that they begin to toast. Stir them continuously; they will burn very easily. When they begin to smell nutty and darken, add in the liquids. It will be hot and sizzly, so be careful. Stir for about 1 minute, and then turn the heat off, cover the pan, and leave the oats to absorb the liquid for a few minutes.

Once most of the liquid is absorbed, add in the sautéed vegetables, arugula and heat together. The oats should be creamy and pretty thick. At the last moment, sprinkle in the nutritional yeast and stir like crazy so that everything is covered thoroughly.

Transfer to a bowl or dish and season to taste. Enjoy!