In a small bowl, whisk together the gochujang, soy sauce and sugar; set aside.
1/4 cup Gochujang sauce, 3 Tbsp Soy sauce, 1 Tbsp Sugar
In a 12-inch skillet over medium-high, heat the oil until shimmering. Add the chicken in an even layer and cook without stirring until browned on the bottom, about 5 minutes. Reduce to medium, then flip the chicken and cook without stirring until browned on the second sides, 3 to 4 minutes.
3 Tbsp Olive oil, 1-1/2 lbs Chicken thighs, boneless and skinless, cut into thirds
Add the garlic and ginger; cook, stirring, until fragrant, about 30 seconds. Add the gochujang mixture and cook, scraping up any browned bits and occasionally turning the chicken, until the sauce has thickened lightly and coats the chicken, 2 to 3 minutes.
3 cloves Garlic, minced, 3 Tbsp Ginger, minced
Garnish with toasted sesame seeds and scallions
1 tsp Toasted sesame seeds, 1 Tbsp Scallions, sliced