Lightly sprinkle salt and pepper over chicken thighs. In a large pan, heat vegetable oil. Brown chicken thighs. Transfer to slow cooker insert. **
Add potatoes and carrots to slow cooker insert.
Remove excess oil, leaving about 2 tablespoon in the pan. Fry onions for about 2 minutes. Add curry powder and cinnamon stick. Continue to fry until fragrant, another 2 minutes. Pour coconut milk into pan. Add salt to taste. Turn off heat.
Pour sauce over chicken, potatoes, and carrots in slow cooker insert. Cover slow cooker and cook on high for 3 hours.
After 2 hours, add frozen green peas and continue to let it cook for another hour.
*A tablespoon of cornstarch may be mixed into the coconut milk for a thicker consistency in the sauce.**Browning chicken thighs is optional. If preferred, raw chicken thighs may be placed in the slow cooker insert.Traditionally, chicken curry consists only of chicken and potatoes. Carrots and green peas may be omitted, if preferred.