Coat the bottom of a slow cooker with olive oil.
Add cubed chicken breasts.
In a medium bowl, whisk together orange juice and all of the other seasonings EXCEPT the cornstarch (or xantham gum; if using)
Pour over the chicken and toss to coat.
Cover and cook on high for 4 hours or low for 6 hours being sure that the chicken is cooked through.
Remove about 2 tablespoons of the liquid and mix with the cornstarch (or xantham gum; if using) to create a slurry.
Cook, stirring often until the sauce thickens to your desired consistency. To speed up the process, you can remove the sauce from the slow cooker, place in a medium saucepan and simmer over medium-high heat until thickened. Then, return to coat the chicken.
Garnish with toasted sesame seeds, sliced green onions, or dried orange zest; if desired.