Walnut Pesto Stuffed Chicken

2 large chicken breasts 1/3 cup walnuts, chopped 4 fresh basil leaves 2 cloves garlic 2 tbsps extra virgin olive oil 1 tsp dried rosemary leaves sea salt and black pepper Using a small food processor, blend together the walnuts, basil, oil and garlic until a chunky paste.  Carefully butterfly each chicken breast (make a…