Chop the herbs in a food processor. With the motor running, drizzle in enough olive oil to make a thick sauce. Season with salt and pepper to taste.
For the meal:
Preheat oven to 190 degrees C. Using a small knife, cut the cores from the tomatoes. Drizzle a little of the herb sauce into each tomato. Then press 1 teaspoon sugar into each tomato and top with 1 teaspoon butter. Place on a baking tray.
Season the chicken. Heat a frying pan with a little oil and brown the chicken on both sides. Place the chicken in the baking tray with the tomatoes and bake 15-20 minutes or until chicken is cooked through.
Place a chicken breast and a tomato on each plate and drizzle with herb sauce.