Prep your beef by slicing against the grain into thin strips, patting dry, then sprinkling with salt and pepper.
Slice bell peppers into strips and mince garlic and ginger.
Mix soy sauce, sugar, cornstarch, and water until smooth for the sauce.
Cook peppers in a teaspoon of oil over medium-high heat for 3-4 minutes and remove to a plate.
Add remaining oil, increase heat to high, and cook beef strips in batches for 5-6 minutes until browned.
Add garlic and ginger, stir constantly for 30 seconds.
Combine peppers and beef in the pan.
Whisk and pour sauce over the pan ingredients, allow it to bubble and thicken.
Simmer for 2-3 minutes until sauce thickens into a glossy coat.
Serve over rice and enjoy!