In a pot, bring 1 cup water and rice to a boil. Reduce heat to low, cover and simmer for 20 minutes.
Preheat oven to 350 degrees F (175 degrees C). Butter a 9x13 inch casserole dish.
Bring a large pot of water to boil. Reduce heat to low and place cabbage leaves in pot. Simmer 4 to 5 minutes, until tender. Drain leaves and set aside.
Heat oil in a skillet over medium heat and cook turkey and onion until turkey is brown and onion is tender. Transfer turkey and onion to a bowl, cool slightly, and mix in cooked rice, egg and 1 can tomato sauce. Season with salt and pepper.
In a separate bowl, mix 1 can tomato sauce, tomato paste, water, brown sugar, lemon juice and Worcestershire sauce.
Scatter carrot slices evenly over bottom of casserole dish. Spread cabbage leaves on a flat surface and place about 2 tablespoons turkey mixture in the center of each leaf. Fold edges of leaves over filling, then roll into logs. Place cabbage rolls seam side down in dish over carrots. Pour sauce evenly over rolls.
Cover and bake 1 hour in the preheated oven. Remove cover during last 10 minutes of cook time. Allow to sit 5 minutes before serving.