Mix soy sauce, wine, oil and ginger (add 1~2 tsp sugar or other sweeteners if you like sweet flavors).
Clean chicken thighs and legs. Remove excess fat and also poke a few times with your knife.
Massage chicken with your hands in the soy ginger sauce and leave to marinate for 2 hours at room temperature.
Preheat oven to 350° F (175° C). In a heavy (oven safe) pan or dutch oven large enough to hold all thighs/legs in a single layer, heat 2 Tbs EVOO over medium high heat. When oil is hot, sear chicken pieces, skin side down for 4-5 minutes or more until golden brown. Turn over and brown the other side for another 4 minutes until golden brown. Remove chicken and set aside.
With the pan still hot, add onion slices and lemon slices. Cook until onions have wilted and brown bits on bottom of pan have loosened. 5-7 minutes. Turn heat off.
Place chicken pieces, skin-side up on top of onion mixture. Pour juice of 1/2 lemon and 1 Tbs of sake or mirin.
Cover and transfer pan to oven and bake for 40 – 45 minutes.