Heat vegetable oil in a Dutch oven over medium low heat (I use a 4 qt one), add ginger, garlic, scallion, star anise, bay leaves and cinnamon stick. Cook and stir until aromatic and the scallions begin to brown, about 1-2 minutes.
Adjust the heat to medium, add in chicken and cook for 1 minute before flipping and cooking another minute.
Add Shaoxing wine, soy sauce, dark soy sauce, oyster sauce, tomato paste and sugar. Stir and cook for about 30 seconds.
Add water, cover and pot and bring it to a boil before turning the heat down to low and maintaining a gentle boil for 30 minutes.
Submerge the potatoes in the stew and cook for another 20 minutes or until the potatoes are soft.