In an open saucepan cook the chicken pieces a few at a time and place the golden brown pieces covered on a plate. In the same olive oil add the finely chopped onion and the leek. Leave to cook for 5 minutes, keep stirring and then add the peppers. Mix all together and then put the chicken back in, turn the heat higher and pour the beer slowly as it rises. Add the sugar and season with herbs, salt and pepper. Turn the heat down and simmer for 1 hour and 30 minutes until the chicken is soft and the sauce has thickened. Serve with rice.