I buy bags of individually flash-frozen chicken breasts and frozen veggies and keep them on hand for nights when I don't feel like spending much time cooking. I can cook a healthy, filling, low-cal, low-sodium meal in 10-15 minutes.
If you have a George Foreman grill, or can get one, I HIGHLY recommend them; they cook with no oil or fat and they cook quickly and thoroughly. My meat turns out juicy and wonderful in less time than it would take to fry it. It's great on hot days, too; doesn't heat up the house!