Stay-In Spinach Mac & "Cheese"

1. If making topping, preheat oven to 350 degrees F. Melt 2 tablespoons vegan margarine over medium heat with the diced onion. Allow to cook until onions are softened, about 5 minutes. Make a roux using the flour, adding 1 tablespoon each time, stirring constantly until thickened to desired consistency.
2. Add the nondairy milk slowly, stirring constantly. Add nutritional yeast flakes, salt and pepper to taste. Allow the entire sauce to thicken over medium heat, until it coats the back of your spoon, about 10 minutes. Turn the heat to low to avoid scorching the sauce.
3. Slowly add the vegan "cheese" shreds and stir constantly over low heat until fully melted and smooth. Add the pasta and fold in the spinach until it is thoroughly incorporated with the sauce. Serve immediately, if not using bread crumb topping, or add to casserole dish.
4. For the breadcrumb topping, use a food processor to blend the toasted bread slices until they resemble coarse crumbs. Melt 1 tablespoon vegan margarine and add oregano. Add the breadcrumbs and mix together.
5. Sprinkle over the casserole and then sprinkle the paprika over the breadcrumbs. Bake in the oven for 30 minutes until topping is browned and casserole is bubbly. A nice dish for a cold winter day in!
Source of recipe: My husband was making his "famous" homemade mac and I stood beside him while I came up with this nondairy version. Since we didn't have enough pasta to split, I ended up adding spinach; delish! Warning: This is not low fat!