In a large skillet, heat the oil until shimmering. Add the pork in a single layer and cook over high heat, turning once, until crisp, 6 minutes. Drain the pork on paper towels and pour off all but 2 tablespoons of the fat from the skillet. Add the kimchi and stir-fry over high heat for 2 minutes. Add the pork and toss. Stir in the soy sauce and transfer to a bowl. Drizzle with the sesame oil and garnish with the scallion.