Clean the chicken thoroughly with water.
Add light soy sauce, fish sauce, salt, brown sugar, minced garlic, ginger slices, and lime juice to the chicken. Rub the seasoning all over the chicken.
Use only the lower white part of the lemongrass. Remove any dry outer layers. Trim off the ends, then cut into shorter pieces. Smash the lemongrass pieces with the back of a knife to release the aroma. Add the lemongrass to the chicken and mix to combine. Marinate for at least 30 minutes, or overnight for best results.
Add 2 tablespoons of cooking oil to the rice cooker pot. Add the ginger slices and lemongrass pieces from the marinade. Place the chicken skin side down into the pot. Close the lid and press the cook button.
Cook until the chicken skin turns golden brown, about 10–15 minutes. Flip the chicken over, then pour the remaining marinade over it. Gently scrape the base of the pot to prevent the sauce from burning. Press cook again and let the chicken cook through completely.
Serve the lemongrass chicken with steamed rice and your choice of sides.
