First, let’s make the sauce: whisk soy sauce, oyster sauce, sesame oil, cornstarch, and black pepper in a small bowl. Heat 1 tablespoon oil in your skillet over high heat—it should shimmer but not smoke. Add the beef in a single layer (don’t crowd the pan!) and cook for 1-2 minutes per side. Remove the beef once browned but not fully cooked through—it’ll finish later.

Add the remaining oil to the same skillet and toss in garlic, stirring for 10 seconds until fragrant. Throw in broccoli, bell pepper, and carrots. Stir-fry for 3-4 minutes until veggies are brightened but still crisp. Return the beef to the pan, pour in the sauce, and toss everything until the sauce thickens (about 1 minute). Remove from heat immediately to avoid overcooking!