Quick Chicken and Spinach

500g chopped chicken thighs, no bones.
1 bunch spinach, chopped in 3 places.
1 onion
1 clove Garlic
1 tsp crushed Ginger
1/2 cup Sake
2 tbsp Soy Sauce
Salt and pepper
Coat chicken in salt and pepper. Fry over a high heat until brown. Add onion and stir. Add garlic, ginger and sake and bring to the boil. Throw in spinach and soy sauce. Simmer for 3-4 mins, or until chicken is done. Season as desired.