Melt the butter in a wide, deep-sided saucepan over medium heat. Brown the chicken well, cooking for at least 3 minutes without moving on each side. Don’t rush this step, remember the colour is the flavour. Remove the chicken and set aside.

Add the onion and rosemary and cook, stirring occasionally for 5 minutes. Add the garlic and cook for another 2 minutes, then pour in the wine. Let it bubble up, then use a wooden spoon to scrape up all the browned on flavour on the bottom of the pan.

Whisk the chicken stock, tomato paste and sugar together, then pour into the pan. Season with freshly ground black pepper, then return the chicken to the pan. Bring to the boil, then reduce the heat to a simmer and cook, covered with a tightly fitted lid for 30 minutes. After 30 minutes, uncover the pan and simmer for a further 20 minutes.

In the last 10 minutes of cooking time, stir through the beans and the chilli flakes (if using). Season with salt and pepper to taste and serve in flat bowls with plenty of fresh bread to mop up the sauce.