Preheat the oven to 350°F.
In a large pan over medium heat, add olive oil and yellow onion and cook, occasionally stirring until onions are translucent.
Stir in garlic, baby Bella mushrooms, cumin, chili powder, coriander, smoked paprika, and salt and pepper and cook until the mushrooms turn a darker brown.
Mix in diced tomatoes, black beans, kidney beans, corn, and mix until well combined. Reduce heat to low and cook for 5 minutes.
In a large bowl, combine the mixture and cooked rice. Transfer to a 9×13-inch baking dish lightly sprayed with cooking spray.
Top with the No-Cheese Sauce and bake uncovered for 25 minutes.
Served topped with the cilantro, green onions, and vegan sour cream
