Cut the boneless skinless chicken breasts or tenders into bite-sized pieces. Ensure they are evenly coated with cornstarch for that delightful texture!

Brown the chicken by heating olive oil in a skillet over medium-high heat. Cook until lightly golden.

Transfer the browned chicken into your slow cooker.

Whisk together the orange marmalade, reduced-sodium soy sauce, white vinegar, sesame oil, ground ginger, minced garlic, and crushed red pepper flakes in a bowl.

Pour the sauce over the chicken in the slow cooker. Gently stir to coat.

Cover and cook on LOW for 2 to 3 hours or HIGH for 1.5 to 2 hours.

Garnish with additional sesame seeds and chopped scallions just before serving.