Sauté vegetables: Heat the olive oil in a large, deep skillet over medium heat. Add the diced carrots, onion, and zucchini, sautéing until soft, about 7 minutes. Then, stir in the minced garlic and sauté for an additional 2 minutes.

Cook lentils: Add the French lentils, vegetable broth, tomato sauce, 1/2 cup of marinara sauce, water, chopped basil, and red pepper flakes to the skillet. Bring to a boil, then cover and reduce heat to a simmer for 35-40 minutes, stirring occasionally until the lentils are tender.

Boil noodles: While the lentil mixture cooks, bring a large pot of salted water to a boil. Cook the lasagna noodles according to package instructions, then drain and lay them flat on a clean surface to prevent sticking.

Prepare cheese sauce: In a small saucepan over medium heat, melt the vegan butter. Whisk in the flour for about 30 seconds, then slowly pour in the almond milk, stirring constantly. Add nutritional yeast, garlic powder, salt, and pepper, bringing to a low simmer until thickened.

Preheat oven: Preheat your oven to 400°F, ensuring it’s nice and hot for baking.

Layer ingredients: Spread 1 cup of marinara sauce on the bottom of a 9x13 baking dish. Layer with 3 lasagna noodles, then top with half of the lentil mixture, half of the cheese sauce, and 2/3 cup of shredded vegan cheese.

Repeat layers: Add another 3 lasagna noodles, the remaining lentil mixture, the rest of the cheese sauce, and another 2/3 cup of shredded cheese to create a second layer.

Final layer: Top with the last 3 lasagna noodles, spread 1 cup of marinara sauce over them, and sprinkle with the remaining shredded cheese.

Bake: Cover the dish with foil and bake for 15 minutes. Remove the foil and continue baking until the cheese is melted and bubbly, about 10-15 more minutes.

Rest before serving: Allow the lasagna to rest for 10 minutes before slicing.