Like one of those Hamburger Helper meals (as is the chili mac). I brown some ground beef (with onion and bell pepper), usually about 3/4 of a pound, which stretches the meat. Boil up some noodles, drain and add to the meat. I use Italian seasoning, salt, pepper and some garlic powder, some diced tomatoes and a little tomato sauce. Let it cook for a while to blend the flavors in.
I set out some cheese (usually Mozzarella, or cheddar) for the boys to add as they like (because doing it in the pan makes a mess to clean, mostly). We like to add a little sour cream if using cheddar.
Mexican casserole is pretty easy, especially if you have a cast iron pan. Brown ground beef with onion and bell pepper (we use a lot of those two things), drain. Season meat with salt, pepper, chili powder (I make my own). Stir well.
Drain a can of corn, add to meat; add diced tomatoes, some tomato sauce. You don't want it too liquid. Spread out in pan (or casserole dish if you aren't using a cast iron pan), put a layer of cheddar (or Mex mix, whatever you like), top with cornbread mix (boxed or make up from cornmeal).
Cook in oven until cornbread is done. Can be served with rice, but we find this is plenty for us. We top with extra cheese and sour cream.
Your chili mac is basically the same as mine, except I make up a chili, boil some noodles, drain and mix it in. Top with cheese and sour cream. Again, another meal that can use a little less meat, and is hearty enough we don't need another dish.