Mary heads to Edinburgh, where she meets runners and their families before the city's marathon, which she has been given the honour of starting. She is joined by her granddaughter Grace, with whom she shares her delicious home-made chocolate rocky road treats, and also visits the Royal Botanic Gardens to meet children from a local school. Inspired by the vegetables growing in the gardens, Mary cooks a fresh pea pesto spaghetti, while other recipes include minted lamb and an eggy bread avocado and ham sandwich