1. In a large pot, bring the water and salt to a boil. Add macaroni and cook until al dente. Drain.
2. In a food processor, make breadcrumbs by pulverizing the bread and 2 tablespoons margarine to a medium-fine texture. Set aside.
3. Preheat oven to 350 degrees. In a saucepan, add shallots, potatoes, carrots, onion, and water, and bring to a boil. Cover the pan and simmer for 15 minutes, or until vegetables are very soft.
4. In a blender, process the cashews, salt, garlic, 1/3 cup margarine, mustard, lemon juice, black pepper, and cayenne. Add softened vegetables and cooking water to the blender and process until perfectly smooth.
5. In a large bowl, toss the cooked pasta and blended cheese sauce until completely coated. Spread mixture into a 9 x 12 casserole dish, sprinkle with prepared breadcrumbs, and dust with paprika. Bake for 30 minutes or until the cheese sauce is bubbling and the top has turned golden brown.

I made a gluten free version of this for dinner tonight and it was DELISH!