Preheat the oven to 375 degrees F.
In a cast-iron skillet, heat olive oil, garlic and onion over medium to low heat until fragrant.
Add in mushrooms, black beans, corn, tomato or salsa, and jalapeño (if using) and let it sauté for 3-5 minutes, stirring often.
Add in taco seasoning and tomato paste and mix well.
Remove from heat and sprinkle half of the vegan cheese evenly on top.
Add tater tots in a single layer across the top.
Bake for 30 minutes.
Remove and sprinkle the rest of the vegan cheese on top. Bake again for 5 minutes.
Remove from oven and let sit for 3-5 minutes before serving.
Option to top with extra vegan cheese, guacamole, salsa, cilantro, hot sauce, vegan sour cream, or lettuce.