Macaroni and cheese
Macaroni and cheese (sometimes referred to as macaroni cheese or mac 'n' cheese in parts of the U.S., Canada and the British Isles) is a common dish, similar to the British dish cauliflower cheese, whose main ingredients are cooked macaroni (often termed elbow macaroni in the US) and a cheese sauce. Cheddar cheese is the traditional choice (or cheddar-like processed cheese).  However, other cheese may be used. Packaged versions are available, consisting of boxed pasta and a cheese powder, to which is added butter and milk (or water). Extra ingredients, like ground beef, canned tuna, ketchup, sliced hot dogs, ham, bacon, peppers, tomatoes, and other vegetables are sometimes incorporated into the dish as well, though some might say that such recipes are no longer "macaroni and cheese."

# Traditional cooking methods
When cooked traditionally, the cheese sauce is often prepared in the style of Mornay sauce, a classical French sauce of butter and flour cooked into a roux, to which milk and cheese are added. Alternatively, the sauce may consist of a custard base with cheese added. The sauce and cooked macaroni are then combined. Often the dish is then baked as a casserole, sometimes with a breadcrumb topping. The resulting dish displays a contrast between a soft interior and crisp exterior that can only be made by dry-heat cooking.
The stovetop version utilizes heat from a stovetop to slowly melt the cheese in order to integrate with the cooked noodles. The sauce  is ultimately made in the same pan with other ingredients mixed separately.
Boxed versions (the stove top method) of the macaroni dish have been available since 1937 and are known for the rich yellow-orange color, resulting from the use of powdered "cheese sauce mix" rather than actual cheese.  This color was memorialized by Crayola in 1993 when they added a "macaroni and cheese" crayon to their selection of colors available in the US.  The color's name was chosen by young Jason Riggs, age 6, after entering Crayola's annual contest. In Canada, boxed macaroni and cheese is commonly known as "Kraft Dinner" due to the preponderance there of the Kraft Foods product.
Anectdotally, macaroni and cheese was invented by Thomas Jefferson, who, in the variant told by Alton Brown of Good Eats, upon failing to receive an Italian pasta-making machine, designed his own machine, made the macaroni, and had the cook put liberal quantities of York cheddar and bake it as a casserole.
Food writer Jeffrey Steingarten describes an 1802 recipe as the "very first recipe ever printed on the back of an American box". Not technically on a box, the recipe was still part of the packaging: it was printed on sheets of paper wrapped around bundles of dried vermicelli and macaroni produced in Philadelphia by one Lewis Fresnaye. The historic recipe:
Take six pints of water and boil it with a sufficiency of salt, when boiling, stir in one pound of paste , let it boil , then strain the water well off, and put the paste in a large dish, mixing therewith six ounces of grated parmisan or other good cheese; then take four ounces of good butter and melt it well in a saucer or small pot, and pour it over the paste while both are still warm. It would be an improvement after all is done, to keep the dish a few minutes in a hot oven, till the butter and cheese have well penetrated the paste.
It may be rendered still more delicate by boiling the pasta in milk instead of water and put a little gravy of meat, or any other meat sauce thereon.