Cantonese-Style Beef, Tomato, and Egg Stir-Fry

1 Prep the beef: Slice filet mignon thinly against the grain. Toss with 1 Tbsp soy sauce, Shaoxing wine, and cornstarch. Let it marinate for 10 minutes.
2 Scramble the egg: Heat oil in a wok or skillet. Add beaten eggs and scramble gently until just set but still soft. Remove and set aside.
3 Cook the beef: Stir-fry beef slices quickly on high heat until mostly browned (about 1 minute). Remove and set aside.
4 Make the tomato base: In the same wok, add onion (if using), garlic, and tomatoes. Stir-fry until tomatoes soften and release juices. Add sugar, soy sauce, and a splash of water if needed. Simmer until saucy.
5 Combine: Return beef and eggs to the pan. Gently stir everything together. Finish with sesame oil and season with salt and white pepper.
6 Serve: Spoon over steamed rice, garnish with green onions, and enjoy.