Finely chop the onion, grate the ginger, and chop the chili pepper and water chestnuts.

Chop the fresh chives.

In a large bowl, combine ground beef, chopped onion, grated ginger, chopped chili pepper, chopped water chestnuts, chopped chives, egg, breadcrumbs, and 1 tbsp hoisin sauce.

Mix well to combine all ingredients.

Shape the mixture into eight patties.

In a small bowl, combine 1 tbsp water, oyster sauce, 1/3 cup hoisin sauce, and crushed garlic.

Reserve 1/4 cup of the hoisin mixture for serving.

Brush the patties with the remaining hoisin mixture.

Heat a grill pan or large skillet with oil.

Cook the patties on the heated grill pan or skillet until browned on both sides and cooked through.

Coarsely chop the gai lan (Chinese broccoli).

Heat sesame oil in the grill pan or skillet.

Stir-fry the gai lan until wilted.

Serve the gai lan topped with the cooked beef patties.

Drizzle the reserved hoisin mixture over the gai lan and patties.