Heat the vegetable oil in a large pot over medium-high heat. Season the beef with salt and pepper and brown in batches for 5–7 minutes. Remove and set aside.

Reduce the heat to medium, add the sesame oil, onion, garlic, and ginger. Sauté for 3–4 minutes until translucent and fragrant.

Add the carrots and bell pepper, cook for an additional 2–3 minutes until slightly softened.

Deglaze the pot with a splash of beef broth, scraping up the browned bits.

Return the beef to the pot, add remaining beef broth, soy sauce, brown sugar, rice vinegar, five-spice powder, and star anise. Mix well.

Bring to a boil, then reduce heat to low, cover, and simmer for 1 hour and 15 minutes, stirring occasionally.

Taste and adjust seasoning with salt and pepper as needed.

Serve over rice, garnished with green onions.