In a large pot, place cored peppers (and optional cored onions) in about an inch of water
Boil the cored peppers until tender (about 10 minutes)
In a large, nonstick skillet, cook the hamburger
*I like to drain the hamburger meat (if necessary) and then use a blender to make the hamburger texture super fine
In the same skillet with the hamburger added back to it, Add the onion, zucchini, tomato, garlic, salt, pepper, 8 oz. of the tomato sauce, and Worcestershire sauce
Continue to cook until all of the vegetables are tender
Mix the rice into the beef mixture
When peppers are tender, drain the water from the peppers and let them cool off a bit
In another large ovenproof pot - or - crock pot,add half of the tomato sauce to the bottom of the pot start filling each pepper to the top with the rice mixture
Place the peppers, standing up in the oven-proof pot, - or a crock pot (over the tomato sauce)
Add a little more tomato sauce to the top of each pepper
Cover the pot, and if you're using the oven (bake at 350 degrees for about 30 minutes) if you're using a crockpot, place it on low for the day
Just before serving, add some tomato sauce from the bottom of the pot to the tops of the pepper, and about 1 Tbsp. of butter to the top of each cooked stuffed pepper
while the peppers are still warm you can add (optional) shredded cheese