Chicken, Sweet Potato and Peanut Stew

Ingredients

• 2 tbsp vegetable oil
• 1 medium onion, ¼ inch dice
• 2 tbsp freshly grated ginger
• 2 tsp mild curry powder
• 1/4 tsp cayenne pepper
• 1 tsp salt
• 28 oz can diced tomato
• 3 cups chicken or vegetable stock
• 3/4 cup peanut butter
• 1 1/2 lbs sweet potato (4 cups), peeled and cut in 1-inch pieces
• 6 skinless chicken thighs, cut in chunks
• 2 chicken breasts, cut in chunks
• 3 cups fresh spinach, chopped
• 8 lime wedges
• 8-16 fresh cilantro sprig