To prepare the cheese sauce, add the cubed potatoes and sliced carrots to a pot of water. Bring to a boil and boil uncovered until tender, about 20 minutes. Reserve 1 cup of water before draining. Drain the remaining water and add the drained potatoes and carrots to a high-speed blender. Add the cashews, nutritional yeast, garlic powder, onion powder, salt, and reserved water to the blender. Blend on high until completely smooth. If needed, add additional water until you reach a smooth consistency.

To prepare the walnut mushroom 'hamburger,' heat the olive oil in a pan over low-medium heat. Add the garlic and onions and cook until soft, about 2-3 minutes. Add the diced mushrooms and cook until soft, about 5-6 minutes. Season with salt, pepper, chili peppers, and oregano. Blend the walnuts until fine crumbs form. Add the walnut crumbs to the mushroom mixture and stir to combine.

In a large pot or serving bowl, and your hot cooked pasta noodles of choice, cheese sauce, and mushroom 'hamburger' mixture. Stir until fully combined. Serve and top with fresh diced tomatoes and basil if desired.