Bake the potatoes - Pre-heat the oven to 400 degrees. Poke each potato with a fork a few times. Rub the potatoes with olive oil. Grind salt and pepper over all sides of the potatoes and rub to evenly distribute. Bake directly on the oven rack for 45 - 60 minutes, until a fork can easily move through the inside. Place a baking sheet below the potatoes while baking to catch any drips. Chop your veggies while the potatoes are baking.
When the potatoes are done baking, heat 3 TBS olive oil in a large wide pot over medium heat. Add all of the veggies, cover, and saute until soft, 10 - 15 minutes.
Gently press each potato with a spatula to smash it slightly. Add a dab of vegan butter, and top each potato with a ladleful of gravy.