Preheat oven to 425 degrees Fahrenheit. Cube veggies and potatoes. Place on a greased baking sheet and bake for 12-15 minutes on each side.
Prepare the lentils in a large pot while the veggies are in the oven. Cook according to package instructions, using vegetable stock instead of water. Once they are done cooking, add in the onion, seasonings, and tomatoes. Set aside.
In a saucepan over medium heat, melt the vegan butter. Add the flour to the butter and mix very quickly to avoid clumps. Slowly add soy milk and reduce heat. Season to taste and stir until desired texture is achieved.
Lower the oven temperature to 400 degrees Fahrenheit. Grease or line a casserole dish. At the bottom, place the potatoes and veggies. Then add the lentils. Pour the sauce on top. Bake for 20-30 minutes with foil on top. Bake for another 5 minutes without foil. Serve and enjoy!
I've tried many variations and carrots and squash are great substitutes for the zucchini and eggplant.
For the lentils, I typically use taco seasoning. You can use whatever you prefer. Italian seasoning also works well with this.
If you are not a fan of lentils, another bean or meat substitute will work.