Cut the heart out of cabbage and remove any outer wilted or brown leaves.
Place cabbage in a pot of boiling water and add enough water to cover the entire cabbage.
Boil for 5 minutes, remove cabbage from water and carefully separate the leaves. Drain well between sheets of paper towel.
Beat the egg in a medium-size bowl.
Peel and grate the onion.
Add the ground beef, egg, rice, grated onion, salt and pepper and mix well.
Lay out cabbage leaves, inside of leaf toward you, and spoon approximately 4 oz of the mixture onto each leaf. Form into a roll—you should get 10 rolls.
Mix crushed tomatoes, water, lemon juice and sugar together in a bowl.
Arrange rolls in a large pot on top of the stove and pour tomato mixture over them, making sure they are covered completely.
Cover pot tightly and cook for 2 hours at medium-low heat.
Remove pot from stove and place in 350 F degree oven, covered, and cook for an additional 2 hours.
Serve with a sprig of parsley or dill and a side of sour cream or plain Greek yogurt.