Heat one tablespoon of olive oil over medium-high heat in a Dutch oven. Add the chicken thighs and cook for 3-4 minutes on each side until no longer pink. Remove the meat from the pot and set aside. Work in batches as it is possible you won’t be able to fit in all the thighs.
Add another tablespoon of olive oil, turn the heat to medium and bring in the onion. Sautee for 4-5 minutes until soft.
Bring in the red pepper, green pepper, garlic, dried oregano and fresh rosemary. Stir well and cook until the garlic is fragrant, for about 30 seconds.
Add the potatoes, pour the broth and stir in the tomatoes. Take the heat to high and bring to a boil. Decrease the heat to low, cover and simmer for 10-15 minutes, stirring from time to time.
Take off the lid and add the olives and chicken thighs. Cover again and cook for 30 more minutes until the meat is cooked through and falls off the bones.
Stir in the sherry vinegar. Season with salt and freshly ground pepper, to taste. Stir again.
Serve warm with rice, quinoa, cauliflower rice a salad or a crusty slice of bread.