Cut napa cabbage into bite-sized pieces. Mince garlic, ginger, and green onion.

In a bowl, mix beef with 1 tsp soy sauce and 1/2 tbsp sake. Massage until liquid is absorbed, then add 1 tbsp cornstarch and mix well.

Heat 2 tbsp salad oil in a pan over low heat. Add minced garlic, ginger, green onion, and 1 tbsp Sichuan peppercorns. Stir until fragrant, then add 1 tsp doubanjiang and mix well.

Add 300ml water and 1.5 tbsp soy sauce to the pan. Bring to a boil over medium heat.

Add napa cabbage and bean sprouts. Simmer over low heat for 7–8 minutes until the cabbage softens. Remove vegetables and place them in a serving dish.

Bring the broth to a boil again. Add beef slices in batches, ensuring they do not overlap. Cook for 3–4 minutes until beef is fully cooked. Transfer beef and broth to the serving dish with vegetables.