Preheat oven to 400 degrees F (205 degrees C).
In a large saucepan heat Vegetable Oil (2 tablespoon) over medium-high heat. Add Onion (1) and Garlic (4 clove) sauté for 3 to 5 mins, or until translucent.
Add Cremini Mushroom (1/2 cup) and sauté for 5 mins, until mushrooms are tender and reduced in size by half.
Add Veggie Ground Round (1 pound), Water (1 cup), Dry Red Wine (1/3 cup), Tomato Paste (2.5 ounce) and Vegan Worcestershire Sauce (2 tablespoon).
Then add Vegetable Bouillon Cube (2 teaspoon), Dry Mustard (1 teaspoon), Bay Leaf (1) and Finely Ground Black Pepper (1/2 teaspoon).
Add Fresh Rosemary (1 tablespoon). Stir and bring to a simmer. Cover and immediately reduce heat to medium low. Simmer for 5 minutes, stirring frequently.
Add Carrot (2), Corn Kernels (1/2 cup), and Green Peas (1/2 cup) to the ground round mixture, and stir until combined. Simmer for an additional 15 minutes. Add more water, 1 tablespoon at a time, if mixture begins to dry out. You want this mixture to be moist, not too wet or soggy. Remove bay leaf and season with Sea Salt (to taste).
In a large pot, bring Potato (1 pound) covered in salted water to a boil and cook for 10 to 15 mins until fork tender.
When potatoes are cooked, strain. Place potatoes back into the pot and add Non-Dairy Milk (1/4 cup), Vegan Butter (3 tablespoon), and Nutritional Yeast (1 tablespoon), and mash until there are no lumps.
Scoop the filling into an 11x7-inch casserole dish and spread out using a spatula.
Spoon the mash over filling and spread out evenly with a clean spatula.
Rough up the surface of the mashed potatoes with a fork. This will create a nice browned crust.
Place the casserole dish onto a cookie sheet and bake for 25 to 30 mins or until the mash begins to brown.
Remove casserole dish from the oven to a cooling rack and let it sit for 15 mins before slicing and serving. Serve with a side of baked beans, and gravy (optional).