Cut the tops off the bell peppers and remove the seeds and membranes. In a large pot, bring water to a boil with 1 tsp salt and 2 tbsp vinegar. Blanch the peppers for about 5 minutes, then remove and cool.
Heat olive oil in a skillet over medium heat. Add chopped onions and grated carrots and sauté for about 5 minutes until softened. Stir in pressed garlic and sauté for another minute until fragrant.
In a mixing bowl, combine cooked rice, lean ground beef, sautéed vegetables, chopped tomatoes, eggs, fresh parsley, dried oregano, Mrs. Dash seasoning, 1 tsp salt, 1/2 tsp pepper, and sugar. Mix thoroughly.
Preheat oven to 350°F (175°C). Spoon the beef mixture into each bell pepper, packing gently. Place stuffed peppers upright in a baking dish.
Pour chopped tomatoes or marinara sauce over the stuffed peppers to coat them well.
Cover the baking dish with aluminum foil and bake for about 30 minutes. Remove foil and bake for an additional 10-15 minutes until beef is cooked through and tops are browned.
Allow the peppers to cool slightly before serving. Optionally, top with a dollop of sour cream. Enjoy warm.