Preheat your slow cooker to the LOW setting.

In a skillet, brown the ground beef over medium heat for 5-7 minutes, then transfer to a bowl.

Sauté the chopped onion, thyme, parsley, red pepper flakes, and salt in the same skillet for 3-5 minutes.

Combine the onion mixture with the browned ground beef.

Chop the cabbage into 1-inch pieces and place them in the slow cooker.

In a bowl, combine diced tomatoes, tomato paste, Worcestershire sauce, and water.

Pour the tomato sauce mixture over the cabbage in the slow cooker.

Cover and set the slow cooker to LOW for 6 to 8 hours.

Check for tenderness, and serve hot over rice.