Stuffed peppers are a great make-ahead. Everything can be cooked and assembled ahead of time, then put in the fridge until it's time to pop them in the oven to heat through. I've heard you can easily make them in a crock pot or pressure cooker, too, though I've never tried it because it's not something I've ever needed to do.
This is also a great "make it once, eat it twice" (MIOEIT) meal -you can make a double batch of filling and put the extra in the freezer. The next time you want to eat it, just thaw the filling, clean and parboil your peppers, shred some cheese, and voila! Stuffed peppers ready for baking in about 15 minutes.
4 green bell peppers (you want decent size ones that can stand up straight)
1 pound ground beef
1/2 large onion, chopped
1 tablespoon minced garlic
1 1/2 cups cooked rice (I prefer brown, but white works, and even Minute Rice will do)
2 cans condensed tomato soup (like Campbell's)
2 cups shredded cheddar cheese, divided
salt and pepper to taste
1. Cut the tops off of the bell peppers. Remove seeds and as much of the ribs as you can with your fingers. Rinse well.
2. In a large pot, bring enough water to a boil to cover the peppers. Add 1 tablespoon salt; when dissolved, add peppers. Boil for four minutes. Remove with tongs, taking care not to tear or puncture them (careful! They'll be full of hot water, drain them carefully!). Place them in an 8x8x2 baking dish.
3. Brown the ground beef with the onions and garlic. Drain the fat off the beef. Add rice, soup, and salt and pepper to taste. It should be fairly loose, but not too soupy. If it's too soupy, you can add more rice or spoon some of the soup out.
4. Cook over medium heat, stirring occasionally, until bubbly. Add salt and pepper to taste. Add one cup of cheese and stir until melted.
5. Spoon the mixture into the peppers. Top with remaining cheese. Refrigerate.
6. When ready to bake, preheat the oven to 350 degrees. Immediately put peppers in the oven, and bake for 45 minutes.
Note: If you're baking them right away, you only need to bake about 30 minutes, since the filling will already be hot.