Season both sides of the chicken liberally with salt and pepper. Heat the oil in a deep saucepan, add the chicken and sear on both sides until golden brown, about 2 minutes on each side. Remove the chicken and add the onions and garlic and cook at medium-low heat until the onions are golden brown, about 10 minutes. Season with salt and pepper, stir in the yellow chile and return the chicken to the pan. Spoon some of the onions over the chicken, cover and cook for 10 to 15 minutes, until chile sauce has completely infused the mixture and the chicken is cooked through. Add the lemon juice and cook another 10 minutes, to allow flavors to meld.