Place the peeled and quartered potatoes into a large pot.
Cover with water and add 1 tsp of salt.
Boil for approximately 15-25 minutes over medium heat (until soft).
Drain the potatoes and return them to the pot.
Add the butter or olive oil, almond milk, garlic powder and salt.
Mash until smooth consistency.
In a large saucepan over medium heat, add 2 tbsp of olive oil, and add the onions, carrots, and celery. Sauté until lightly browned and caramelized, about 5 minutes.
Add the garlic and sauté for 2 minutes.
Add flour, thyme, soy sauce, Dijon, salt, pepper and tomato paste and stir well for 2 minutes.
Add vegetable broth, lentils, peas, and corn and stir well. Simmer for 5-10 minutes until sauce has thickened.
Transfer the vegetable mixture to a 9x9 or 9x11 baking dish.
Spread the mashed potatoes in an even layer over the top of the vegetables.
Make a pattern on the potatoes, by using a fork and dragging it along the top of the potatoes, in a criss-cross pattern.
Preheat the oven, select Bake, set to 400°F for 20 minutes, then press START.
When preheated, place dish on a baking sheet to catch any overflow of the sauce, then insert at the Bake level.
When cook time is completed, carefully remove from oven and let rest 15 minutes before serving.