Peel and chop the onion. Deseed and roughly chop the red and green peppers. Peel and finely chop the garlic cloves.
On a chopping board, pull the skin from the chicken thighs.
Heat the olive oil in a casserole on medium-high heat and add the chicken thighs, bone facing up. Season with salt and black pepper and brown on all sides for 5 minutes. Remove the chicken and set aside.
Add the onion and peppers and fry over medium low heat for 4-5 minutes to soften. Add the garlic and fry for another 1 to 2 minutes. Add the flour and cook for another couple of minutes.
Add the paprika, bay leaves and chicken stock and stir until everything is combined and you have a silky smooth sauce.
Add the chicken back to the pot and gently stir. Bring to boil and reduce heat to low, cover the pot with a lid and cook for 45-50 minutes.
20 minutes before the end of cooking, remove the lid, add the fresh thyme and the drained and rinsed butter beans. Allow to bubble away and reduce slightly. Remove the bay leaf before serving.
Season with salt, black pepper and paprika, and serve.