In a mixing bowl, whisk together gochujang, soy sauce, honey, minced garlic, grated ginger, and water until smooth to form the sauce.
Heat the vegetable oil in a skillet over medium heat until shimmering.
Add the bite-sized chicken pieces to the skillet in a single layer and cook, stirring occasionally, until browned on all sides, about 5–7 minutes.
Pour the prepared sauce over the browned chicken, reduce heat to low, and simmer uncovered, stirring occasionally, until the chicken is cooked through and the sauce thickens, about 10 minutes.
Remove from heat and garnish with sliced green onions and sesame seeds before serving.
