Cook the rice and allow it to cool slightly.
Preheat the oven to 350° F
Bring a large pot of water to a boil. Cut the tops off the peppers and clear out the seeds. Add a pinch of salt to the water, then boil the peppers just until they change color, about 3 minutes. Drain them and set them aside to cool.
Heat 4 T of oil in a large skillet over medium heat. Add the onions and cook about 5 minutes, or just until translucent. Add the chopped garlic and cook until aromatic. Remove from heat and add the ground beef, mixing until partially cooked.
Transfer to a large mixing bowl and add the tomatoes, oregano, salt, pepper and rice. Mix well.
Place the peppers in a baking dish and drizzle the inside and top of the peppers with olive oil. Stuff the peppers with filling.
Combine ketchup, Worcestershire sauce, tabasco sauce and ¼ c. water in a small bowl, then drizzle the top and sides of the peppers. If there is leftover filling, put some around the peppers in the baking dish. Bake 45 minutes.