Pour enough peanut oil to lightly coat bottom of wok or large skillet into either said vessel preheated over medium high heat. Add onion and garlic and cook, stirring, until garlic is golden. Remove and keep warm.
Sprinkle beef liberally with salt and freshly ground black pepper. Add 4 beef slices and stir-fry until no longer pink outside and well browned. Remove and repeat until all beef has been cooked.
Add chiles, carrots, soy sauce, honey, vinegar, and scallions and stir-fry until vegetables are lightly browned around edges.
Add cooked ingredients and toss until heated through. Sprinkle with sesame seeds before serving.