Preheat the oven to 375 degrees Fahrenheit and lightly grease a 9x13 casserole dish.
In a medium-sized skillet over medium heat, heat 1 tablespoon of avocado oil (or another neutral cooking oil). Add diced onion and sauté for 2-3 minutes, or until fragrant and softened.
Add in defrosted vegan ground beef and cook until browned, 5-7 minutes.
Stir in vegan Worcestershire sauce and salt and pepper to taste.
Transfer the vegan beef mixture to the casserole dish and spread evenly in the bottom.
Layer in the corn, green beans, vegan condensed cream of mushroom soup, and cheese shreds. If desired, toss to combine or leave as layers (see photos in post for reference).
Add a single layer of tater tots (24 ounces should be the perfect amount to cover the entire top.
Bake for 40 minutes, or until the tater tots are golden and crispy.
Remove from oven, top with diced parsley, and serve immediately while hot.
Store any leftovers in the refrigerator for up to 3 days.
To Freeze: Lightly grease a disposable baking dish, then follow steps 2-7 as written. Then tightly cover casserole dish with a layer of saran wrap, then 2 layers of tin foil. Label the top with recipe name, date it was frozen, and cooking instructions. Bake from frozen at 375 degrees Fahrenheit for 75 minutes, or until warmed through. This tater tot casserole will freeze well for up to 3 months.
Prep time does not include making the vegan condensed cream of mushroom soup recipe.
Favorite freezer tools: I use these disposable baking pans to freeze whole casseroles in. Or, if you'd like to freeze single serve portions, divide the casserole ingredients amongst Souper Cubes freezer cubes and freeze small portions before baking. For full freezer instructions, view the complete recipe card notes down below.