Place the beef in the slow cooker and spread the peppers and onions over the top.
Mix the garlic, sugar, pepper, broth, worcheshire sauce and soy sauce together and pour all over the top.
Cover and cook on low for 6 hours or high for 4 hours.
When the beef is tender mix the cornstarch with the cold water and mix together.
Stir in the cornstarch slurry into the slow cooker and stir together till the sauce is thickened.
Serve over white rice with a sesame seed garnish.
ENJOY!