Place chicken thighs on a plate. Sprinkle ½ teaspoon salt and curry powder all over chicken. Turn with a pair of tongs to get them well coated.
Wash and drain rice in rice cooker pot 3 to 4 times. Add salt and coconut milk. Top with water until the 1 cup mark (approximately 1 cup/240ml) on the rice cooker insert. Wipe the exterior of the pot dry. Place in the rice cooker, cover with the lid, and press the cook button.
Heat vegetable oil in a medium pan. Pan fry chicken thighs for 2 minutes. Flip the chicken thighs. Add onion and continue to fry for 2 more minutes. Turn off stove.
Remove the rice cooker lid. Transfer cooked onions to the pot. Add frozen green peas. Stir to get the ingredients well mixed. Place chicken on the top. Cover and allow it to cook until the cook button switches to keep warm. Let it sit for 5 to 10 minutes before serving.