Slice the chicken lengthways to form a pocket and stuff with the Stilton. Wrap each breast tightly with Parma ham. Heat the oil in a non-stick pan and fry the chicken for two minutes on each side, or until pale and golden. Transfer to the oven for roughly 10-15 minutes, or until cooked through. Meanwhile, make the mash by boiling the sweet potato in salted water for ten minutes, or until soft. Drain and mash the potato with the butter. Season with salt and freshly ground black pepper. Stir in the thyme, followed by enough cream to make a smooth mashed potato. For the broccoli and stilton sauce, whisk together the contents of the soup mix, along with 350ml cold milk and 100ml cream in a small saucepan and heat gently stirring constantly until the soup is thick and glossy. When ready to serve, place the sweet potato mash in the middle of your serving plates. Cut each breast into slices diagonally and place fanned out over the mash. Serve some cooked vegetables on the side and pour over the delicious broccoli and stilton sauce.