In a small microwavable bowl add the water and the beef bouillon cubes. Place in the microwave for 30 seconds, mix until dissolved. I use the back of a spoon or the tip of a whisk to break up the bouillon cubes. (If you don't have a microwave, boil your water on the stove-top).
Add the soy sauce, Worchestershire sauce, ginger, garlic powder, pepper, brown sugar and cornstarch to the bowl with the water and bouillon. Whisk until smooth. (Add the red pepper flakes if you desire). Pour this mixture into the slow cooker.
Add the beef, bell peppers and onions onto the sauce in the slow cooker.
Cover and cook on LOW for 5 hours.
1 cup of sliced mushrooms can be added to this recipe. Though the sauce will be slightly thinner due to how much moisture mushrooms contain.Cut the onion and bell pepper into thick slices so they will stay intact during the long cooking time it takes to get the beef tender.Serve over white or brown rice, spaghetti noodles or quinoa. (Not calculated in the nutrition)Refrigerate leftovers for up the 3 days or freeze for up to 3 months.Can I use beef broth instead of bouillon cubes?You can if you are in a pinch. Though I use bouillon cubes and a little amount of water so the sauce is potent. The meat and vegetables will let off their own moisture and dilute the concentrated sauce.To make into a freezer dump meal:Add the raw beef, onion and peppers to a freezer ziplock bag. Mix up sauce mixture, though let it cool before adding to the bag. Freeze for up to 3 months. Thaw in fridge when ready to use, then add contents to the slow cooker and cook according to recipe directions.