Season chicken: Lightly season each chicken breast on both sides with salt and pepper then sprinkle with the herbs and paprika (adjust the amounts of herbs and paprika to suit your taste). Set aside.
Brown chicken: In a large shallow pan heat the oil then add the chicken and cook for about 2 minutes on each side over a medium heat until lightly browned. Transfer the chicken to a large plate leaving the juices in the pan.Preheat the oven to 400F/200C/gas mark 6.
Cook onion: To the pan add the chili flakes, onion and garlic and cook gently for 3-4 minutes until the onion is softened stirring often. Pour in the wine and cook for 2 more minutes.
Add tomatoes: Add the tomatoes, tomato paste, salt and pepper to taste. Stir thoroughly, cover and simmer for 10 minutes stirring occasionally. Stir in the balsamic vinegar, taste the sauce and adjust the seasoning as needed.
Add chicken: Tuck the chicken breasts into the sauce and pour in any leftover chicken juices. Scatter chunks of feta over the sauce.
Bake: Place in the centre of the oven and bake for about 20 minutes or until the chicken is cooked through. Try not to overcook it. Remove from the oven and serve!
Notes
Try not to overcook the chicken. If after 20 minutes in the over you pierce the chicken gently with a fork and the juices run clear your dish is ready. For very large chicken breasts you may need to add on another 5 minutes of cooking time.
Best served immediately. Leftover chicken with tomato sauce can be refrigerated, covered, for up to 3 days. Reheat individual portions in the microwave.
Freeze in an airtight container for up to 3 months. Defrost overnight in the fridge.