How to Make It
Preheat the oven to 425°. Season the chicken breast with 1/8 teaspoon each of sea salt and freshly ground pepper. In a small pan, heat the extra-virgin olive oil over medium high heat. Add the chicken and cook for 1 minute. Turn the chicken, reduce the heat, cover the pan and cook for 8 minutes. Remove from the heat and leave covered for 10 minutes, then shred the chicken with 2 forks.
Scrub the sweet potatoes well and cut into 2-inch dice. In a small pot of boiling salted water, cook the sweet potatoes for 10 minutes, until they are soft. Drain and roughly mash the sweet potatoes.
In a medium bowl, combine the cream cheese, water, soy sauce, Dijon mustard, sage, garlic and the remaining sea salt and freshly ground pepper and whisk to combine. Stir into the mashed sweet potatoes.
In an 8-inch-square baking dish, combine the shredded chicken, onion, egg noodles and the sauce and mix thoroughly. Cover the dish with aluminum foil and bake for 10 minutes. Uncover the dish, stir well and bake for 15 minutes, or until the noodles are cooked and the sauce has thickened. Remove from the oven and let sit for 5 minutes before serving.