Kinda minimalist, but the right spices make it amazing.
1 large deep baking dish (I have a rectangular pyrex dish, works great)
1.5-2 lbs ground beef
8 ounces each of diced: onion (I'm not a fan of white onions), tomato, green pepper
1 jar (26 oz) of pasta sauce (the fancy chunky stuff really pays off here)
(optional) pepperoni slices
(optional) diced jalepeno (pickled)
(optional) shredded cheese, your choice, at least 1 cup
Brown and crumble your hamburger. DRAIN! Seriously, don't ever add undrained beef to anything. I've made that mistake before, and ruined a lot of good food doing it. There is absolutely nothing you can do to fix it, either. Thus, DRAIN IT!
If you want, season your beef. I prefer seasoning after draining so I don't pour so many spices down the drain.
Mix veggies (raw) and ground beef in the dish. Try to get them distributed. My local grocery carries pre-diced veggies, in handy 8-oz portions. I love it.
If you like, mix in or layer on pepperoni at this point. And/or mix in your jalepenos.
Top with pasta sauce. Be sure and spread it evenly.
Bake for an hour and a half (or two) at 350F.
If you like, top with at least 1 cup of your cheese of choice, and broil for a few minutes. Don't be a numbnuts like Nimmy and leave it alone! You know that saying about watched pots and boiling? Total bull. This cheese absolutely WILL burn if you're not careful (trust me on this one) forcing you to peel it off and start again.
There you have it - a trap! Uh, casserole!
You can make it more portion-friendly by making patties instead of crumbled beef.