Preheat your oven to 350°F / 180°C. Lightly oil a 9 × 13-inch (23 × 33 cm) casserole dish.
To begin the potato topping, cut the peeled potatoes into thirds and place them in a large pot of boiling water.
Cook until tender, about 15-20 minutes.
While the potatoes are cooking, prepare the filling.
Heat 1 tablespoon (15 ml / 0.5 fl oz) of oil in a large skillet over medium heat.
Add the diced onion, celery, and minced garlic, and cook for 3-4 minutes, until the onion is soft and translucent.
Turn off the heat.
Add the crumbled veggie ground round, vegetarian Worcestershire sauce, tamari, tarragon, pepper, and optional salt to the skillet.
Stir everything together until thoroughly combined.
Transfer the filling mixture to your prepared casserole dish.
Spread it out and pack it down into an even layer.
Sprinkle the corn kernels evenly over the top of the filling.
Once the potatoes are tender, drain them well.
Add the olive oil, soy milk, salt, and pepper. Mash until smooth and fluffy.
Carefully spread the mashed potatoes over the corn layer, covering the entire surface.
Sprinkle the top with paprika.
Bake for 20 minutes, or until the pie is heated through and the filling is bubbly at the edges.