• Pre-heat oven to 350 F (177 C).

Making the Mashed Potato Topping

• In a large pot of boiling water, let potatoes (peeled and cubed) cook for about 20 minutes or until fork tender.
• In a stand mixer, or with a hand mixer, blend together the cooked potatoes, salt, and soy milk until very creamy.
• Add in the vegan cheddar and Parmesan shredded cheeses.

Making the Filling

• In a medium heat skillet (large), cook the onion, garlic and mushrooms for 5 minutes.
• Add in the TVP and vegetable broth. Stir well.
• Add in the nutritional yeast, onion powder, garlic powder, basil, soy sauce, salt, Worcestershire sauce, and thyme and mix together well. (I like to add all of the seasoning in before the liquid from the vegetable broth cooks off so that the flavors are evenly distributed.
• Add in the peas and corn and continue to cook for another 15 or so, stirring regularly to avoid burning. The TVP should no longer be soggy when it's ready and the veggies should be cooked but not mushy.

Assembling and Cooking

• In a large casserole dish, evenly spread the filling out.
• Add the mashed potato topping on top of the filling and smooth it out with a spatula.
• Bake in oven for 20 minutes. You will likely need to broil for a couple minutes at the end to get that classical browned mashed potato look.