Yukjeon (Pan-fried battered beef)

Name: Yukjeon (Pan-fried battered beef)
Cuisine: American, Asian
Ingredients: 1 pound thinly sliced beef (any tender cut such as loin and rib eye); 1/2 cup sweet rice flour (chapssal garu, 찹쌀가루); oil for pan-frying; 2 scallions (thinly sliced); 1 tablespoon soy sauce; 1 teaspoon rice wine; 2 teaspoons water; 1 teaspoon sesame oil; 1 teaspoon sugar; pinch pepper; 1/2 teaspoon minced garlic; 1 teaspoon hot mustard (gyeoja, 겨자); 1 teaspoon hot water; 1 teaspoon soy sauce; 1 teaspoon vinegar; 1 teaspoon sugar; pinch salt