Add butter to a pan over medium heat.
Slice mushrooms and chop onion then sauté for 10 minutes or until onions are translucent.
Lower heat and continue cooking for about 5 minutes or until onions are soft and caramelized; season with salt.
Add in minced garlic and cook for 1-2 minutes or until fragrant.
Stir in vegetable broth and bring to a boil, reduce heat then add oats and cook for 5-10 minutes until oats are tender and broth is absorbed.
Stir in spinach and halved cherry tomatoes and continue cooking until wilted and softened.
Add to a bowl. If desired, top with fresh herbs, avocado, red pepper and cheese