Heat oil in a skillet over medium-high heat. Add frozen dumplings and cook until the bottoms are golden brown.
Pour in water, enough to submerge the dumplings halfway. Cover and reduce heat to medium. Steam for about 10 minutes or until the water almost evaporates.
In a bowl, combine Gochujang, soy sauce, rice vinegar, sesame oil, toasted sesame seeds, sugar, and scallion greens. Mix well.
Pour the sauce over the cooked dumplings and enjoy!