Heat the olive oil over a high heat in a large casserole dish and brown the chicken breasts on both sides. Remove from the pan and set aside.
Bring a pan of lightly salted water to the boil and simmer the new potatoes for around 15 minutes until tender. Meanwhile, add the onion pepper, courgette and garlic to the frying pan and fry for around 5 minutes, until they start to soften.
Pour in the wine and let it bubble for 1 minute. Stir in the stock, tomato puree and red pesto.
Return the chicken breasts to the pan, lower the heat, cover and simmer for 20 minutes until the chicken breasts are cooked through.
Stir in the creme fraiche and olives and season with black pepper.
Serve with the new potatoes and basil leaves sprinkled over the top.