Marinate the beef: Slice the beef thinly and place in a bowl. Add minced garlic, 1 teaspoon cornstarch, 1 teaspoon sugar, 1 tablespoon soy sauce, 2 tablespoons water, 2 teaspoons sesame oil, and 1 teaspoon black pepper. Mix well and let marinate for 20 minutes.

Prepare the vegetables and noodles: Cut the scallions into short pieces and slice the onion into wedges. Tear the pho noodles into strands.

Stir-fry the beef: Heat 2 tablespoons cooking oil in a pan. Add half of the onion and stir-fry until fragrant, then add the beef and stir over high heat. When the beef is just cooked, turn off the heat and transfer to a bowl.

Make the stir-fried pho: Add 1 tablespoon cooking oil to the pan. Add the pho noodles and pour in the stir-fry sauce. Gradually add the sauce and toss until the noodles are evenly coated and flavorful. Then add the beef, the remaining onion, scallions, and bean sprouts. Stir quickly so the vegetables stay crisp, then turn off the heat.

Notes: Use wide pho noodles for a more attractive and delicious dish. For best results, stir-fry only 1 to 2 servings at a time instead of a large batch.