the recipe here, and I followed it pretty closely. Here's what I did, and each serving was 572 calories for 12 servings.
1 lb elbow macaroni
12 slices bacon, chopped
4 T reserved bacon fat
1 onion, finely chopped
1/2 c beef broth
3 T Worcestershire sauce
6 T butter
5 T flour
3 c milk
4 1/2 c sharp cheddar cheese
1/3 c ketchup
about 1/4 c mustard (more or less to taste)
2 T sweet pickle relish
1 T hot sauce (I used a little less Tabasco)
Top with lettuce, tomatoes, onions, some reserved bacon, and/or pickles
Cook the pasta in well salted water, then drain and set aside.
Cook the bacon until crisp, then when finished cooking remove to a papertowel lined plate. If you have more than 1/4 c bacon grease, remove some of it. Add the ground beef, then add in the onions and season with salt and pepper. Cook until the beef is cooked and the onion is softened, then add in the broth and Worcestershire and reduce the heat to low.
In a large pot, make a roux with the butter and flour, then add in the milk, whisking the entire time. Season well, then add in the cheese, and stir until melted. Add in the ketchup, mustard, relish and hot sauce. Combine this with the pasta, then combine that with the meat and most of the bacon (or all the bacon if you don't want any to sprinkle on top). Serve with desired garnishes.