Step 1

Add the tomato sauce, tomato paste, water, dry white wine, spices, bay leaves, sugar, and garlic to the slow cooker and mix well. Season with salt and pepper.

Step 2

Add the flank steak to the slow cooker and coat it on both sides with the tomato sauce mixture.

Step 3

Top it off with the onions and peppers, cover, and set it to high for 4 1/2 hours or on low for 9 hours.

Step 4

Once the beef is completely tender, remove it from the slow cooker and shred it using 2 forks.

Step 5

Place the shredded beef back into the slow cooker and mix it well. Season with salt and pepper if needed. Cover and cook on high for an additional 20 minutes. Serve warm and enjoy.