Combine all-purpose flour and salt in a large mixing bowl. Gradually add warm water, stirring until a shaggy dough forms. Knead on a floured surface for 6–8 minutes until smooth and elastic. Cover and rest for 30 minutes.

Mix ground beef, chopped green onions, minced garlic, soy sauce, sesame oil, grated ginger, black pepper, and optional chili flakes in a separate bowl until evenly combined.

Roll the rested dough into a cylinder, slice into equal portions, and flatten each into a small disc. Roll out each disc into a thin 3-inch circle.

Place a spoonful of filling in each wrapper’s center. Fold and pinch edges tightly to seal. Optionally, shape into rose-like spirals by twisting and sealing the edges.

Bring a large pot of water to a boil. Cook dumplings in batches for 4–5 minutes until they float. Alternatively, pan-fry with oil until golden, then steam with water covered until cooked through.

Whisk chili oil, soy sauce, rice vinegar, honey, sesame seeds, and chopped green onions in a bowl to make the sauce.

Toss cooked dumplings with the chili oil sauce until coated and glossy. Garnish with extra sesame seeds and green onions. Serve hot.