Hungarian Chicken Paprikash (Paprikás Csirke)

Ingredients:

• 1 kg (2 lb) chicken pieces (thighs/drumsticks preferred)
• 1 large onion, finely chopped
• 2 tbsp vegetable oil or lard
• 2 tbsp sweet Hungarian paprika
• 1 tomato, chopped (or 2 tbsp tomato paste)
• 1 green bell pepper, chopped
• 200 ml (¾ cup) sour cream
• 1 tbsp flour (optional, for thickening)
• Salt and pepper to taste
• Water or chicken broth as needed