Peel and chop the potatoes. Cook in salted water for 15 minutes, or until easily pierced with a fork.

In a large pan, heat vegan butter or olive oil over medium heat. Add the chopped onion and garlic. Sauté for around 5 minutes, stirring occasionally, until the mixture becomes tender and fragrant.

In a large bowl, mash the potatoes. Mix in the sautéed onion and garlic, plant-based milk, thyme, rosemary, nutritional yeast (if using), salt, and pepper. Add optional peas, spinach, or tofu for extra flavor.

In a bowl, mix flour and salt. Incorporate the vegan butter into the mixture by cutting it in until it forms coarse, pea-sized crumbs. Slowly incorporate cold water, one tablespoon at a time, until the dough begins to come together.

Shape the dough into a disc, wrap it tightly in plastic wrap, and refrigerate for a minimum of 30 minutes.

Roll the dough on a floured surface until it's large enough to line your pie dish.

Place the rolled-out dough into your pie dish. Trim off any excess.

Spoon the mashed potato mixture into the crust and smooth it out.

Add a top crust or leave it open-faced. Sprinkle with herbs or breadcrumbs if desired.

Preheat the oven to 375°F (190°C). Place the pie in the oven and bake for 35-45 minutes, or until the crust turns a golden brown.

Let the pie rest for 10 minutes before cutting into it. Then, dig in and enjoy!