Peel and chop potatoes and add to pot with water. Simmer for 20 minutes until tender. If you are using sweet potatoes, I highly recommend roasting them in the oven at 400 0 F until tender 45 minutes.
If using dry lentils, sort and rinse add 1 cup of dried lentils into a pot with 3 cups of water and cook until tender, about 30 mins. You can also cook in Instant pot.
Preheat the over to 400 degrees F.4. While potatoes are cooking heat oil or water in a medium skillet or pan. Add the onions and cook until nearly translucent. Add the garlic and mushrooms and continue to sauté until the onion is golden. At the same time peel and chop the carrots. Add them to sauce pan with water and bring to boil and cook until tender, drain and set aside.
Add the cooked lentils, vegetable broth, bring to a boil. Add soy sauce, thyme, savory, and salt and pepper. Cook for 5 minutes. Combine the cornstarch with 3-4 tbsp of water to dissolve and make a slurry. Stir into the lentil mixture.
Drain and mash with plant-based milk until cream and smooth. If using sweet potatoes, cool, peel and mash well.
To assembly the dish, start by layering the lentil and mushroom layer. Top with the cream corn or corn niblets. Then layer the cooked carrots and finally top with mash potatoes or sweet potatoes. Bake in over for 25-30 minutes and enjoy.