Spray the slow cooker with non-stick cooking spray.
Preheat the slow cooker to the desired temperature - high or low.
Add orange marmalade, soy sauce, vinegar, sesame oil, and ginger to the slow cooker and stir.
Cut the chicken into cubes and toss the cubed chicken pieces with the cornstarch.
Cook the chicken chunks in extra virgin olive oil until they are browned on all sides. You will need to do this in batches.
Pour the browned chicken with juices directly into the slow cooker. Cook on high for 2 hours or low for 4 hours.
Serve with rice and garnish with mandarin orange slices, green onions, sesame seeds.