Saute ground beef and onion in the same pan over medium heat. Cook until the meat is cooked through and no longer pink, breaking up with a spatula as you go.
If your meat is quite fatty, you can drain some fat at this point.
Add beans, ketchup and spices. Combine in the pan and cook on medium for about 5 min. Turning mixture in pan every couple minutes.
After 5 minutes, remove from heat. Fill compartmental meal prep containers with shredded cheese, romaine lettuce and the beef and bean mixture. Keep in fridge for up to 3 days. Reheat the beef and bean mixture before eating.
If eating right away, serve on a plate of romaine lettuce with some shredded cheese and Doritos.