Preheat oven to 350 degrees F. Get out a 2-½ quart casserole with a lid.

In a pan over medium heat, melt 2 tablespoons butter. Cook onions in melted butter until soft. Add beef and rice and cook for about 3 minutes, breaking up beef as it cooks. Put mixture into prepared casserole. Arrange cabbage over beef mixture.

In another pan over medium heat, melt remaining 4 tablespoons of butter. Blend in flour and cook until bubbly. Remove from the heat and stir in 1 cup of water, tomatoes, garlic, ketchup, tomatoes, parsley, salt, and pepper. Simmer, stirring, for 5 minutes. Pour over cabbage. Cover and bake for 30 minutes.