1Heat the vegetable oil in a large pot over medium heat.
Add the chicken thighs and cook until browned on all sides.
Add the minced ginger and garlic, and cook for another 2 minutes.
Sprinkle the baking soda over the chicken and stir well.
Add the diced onion and cook until softened.
Stir in the Japanese curry powder and cook for 1 minute.
Pour in the vegetable stock and bring to a boil.
Add the mashed banana, sliced carrot, diced potatoes, bay leaf, and star anise.
Reduce the heat and simmer for 20-25 minutes, or until the vegetables are tender.
Stir in the soy sauce, chunou sauce, tomato paste, and cocoa powder.
Simmer for another 5 minutes, stirring occasionally.
Remove the bay leaf and star anise before serving.
Serve hot with steamed rice or your preferred side.