1) Heat the oven to 180c. Find a large roasting tin. Halve the chilli, put in a food processor with the tomato puree, olive oil and garlic. Whizz to a paste, and then spread over the chicken. Add the chicken and potatoes to the tin with a good grinding of black pepper and some salt. Mix everything together, add the thyme and roast for 30 minutes.
2) Add the tomatoes for 15 minutes until the tomatoes have softened and the chicken is cooked.