Combine chicken with ginger, garlic and chiles.
Marinate for 1 hour.
In a large pot, heat oil.
Add onion and celery and saute for a few minutes until softened. Add chicken and saute another few minutes.
Add water or chicken broth and bring to a boil.
Add pumpkin, carrots, bamboo shoots and potatoes.
Reduce to a simmer and cook for 10 minutes, until vegetables are cooked through.
Add spinach, salt and black pepper.
Cook for another 5 minutes, until spinach wilts.