Cut the tops off the peppers. Remove and discard the stems, then finely chop the tops; set aside. Scoop out the seeds and as much of the membrane as you can. Place in a plastic bag or other fridge container.Heat 2 tablespoons of the olive oil in a large skillet over medium-high heat. Add the beef, season with salt and pepper and cook, breaking up the lumps, until the meat is cooked through. Remove to a plate.Add a little more olive oil to the pan. Add the onions and chopped peppers and cook until beginning to soften, 3 to 4 minutes. Add the garlic and zucchini and cook for another minute. Add the tomatoes and season with salt and pepper. Cook until everything is heated through, then stir in the beef and rice. Taste and adjust the seasoning. Stir in 1 1/2 cups of the cheese. Allow the mixture to cool and store it in a fridge container. Store the extra cheese in a small container. (All ingredients can stay in the fridge for up to 3 days.)When you're ready to make dinner, preheat the oven to 350 degrees F.Place the peppers cut-side up in a baking dish just large enough to hold them upright. Fill the peppers with the rice mixture and top each with a sprinkle of the remaining 1/2 cup cheese. Pour a small amount of water into the bottom of the baking dish. Cover with foil and bake for 30 minutes. Uncover and bake until the peppers are soft and the cheese is melted and lightly browned, another 15 to 20 minutes.Serve piping hot!