to make foil collar for slow cooker, most slow cookers have a hotter side that can cause casseroles and other dense dishes like meatloaves to burn. Line with a foil collar: Layer and fold sheets of heavy duty foil until you have a six layered foil rectangle. Press the collar into the back side of the slow cooker insert; the food will help hold the collar in place during cooking.Source unknown
line a slow cooker with foil collar and coat with vegetable oil spray. Bring tomatoes, evaporated milk, condensed soup, water, 1 teaspoon salt, mustard and cayenne to simmer in a large pot. Slowly whisk in cheddar and Monterey Jack until completely melted, then stir in macaroni.
Transfer macaroni mixture to prepared slow cooker. Cover and cook until macaroni is tender, about two hours on high. Remove foil collar, gently stir pasta adding hot water as needed to loosen sauce consistency. Season with salt and pepper to taste. Sprinkle with toasted breadcrumbs if using and serve.
Toasted breadcrumbs: process two slices high quality white sandwich bread, torn into pieces, to coarse crumbs in food processor, about 10 pulses. Melt 2 tablespoons butter in 12 inch skillet over medium heat. Add bread crumbs and toasts, stirring often, until Golden Brown, 5 to 7 minutes. Transfer bread crumbs to bowl and season with salt and pepper to taste. Makes about 1 cup.