BOIL CABBAGE IN SALTED WATER 3-4 minutes. Drain and reserve 2 1/2 cups water. Cool cabbage, core and remove 12 large leaves. Spread leaves out flat. Saute onion in 2 tablespoons butter until softened, then mix with beef, rice, 2 teaspoons salt and pepper. Put a spoonful of the mixture in the middle of each leaf, fold up sides, roll up and secure with a toothpick. Place the rolls in one layer in a large pot, add reserved water, lemon juice and remaining butter. Cover and simmer 1 hour. Remove cabbage rolls from pot. Mix flour paste into cooking liquid and cook 3-4 minutes until thickened. Add remaining salt and white pepper. Pour over cabbage and serve.