I made baked cheesy pasta shells today. I used jarred marinara added to sautéed onion, peppers and mushrooms to bulk it up. I also made a vegan bechamel which is basically:
3 tablespoons margarine
1 1/2 tablespoons flour
1/4 cup nutritional yeast
1 1/2 cup soymilk
1/2 tsp salt
Pinch of nutmeg
Melt margarine over med heat. Whisk in flour and nutritional yeast. Slowly add soymilk little by little and stir constantly until thickened. Add salt, nutmeg and black pepper.
So then I layered cooked pasta, bechamel, vegan cheese, red sauce two times in a baking dish. Top layer with more cheese and bake 30 - 35 minutes 375 degree F oven.