Preheat oven to 425˚F.
Place the potatoes in a pot, cover with water and bring to a boil. Salt water and cook potatoes to tender.
Brush the inside of a 12-cup muffin tin with EVOO.
Heat a medium skillet over medium-high heat with two turns of the pan of EVOO. Add apples, celery and onion, and cook until softened, about 5-6 minutes.
In a large bowl, combine turkey with breadcrumbs, egg, poultry seasoning, softened apples, celery and onion mixture, salt and pepper. Separate mixture into 12 equal portions and shape into muffin cups. Bake for 12-15 minutes.
Drain cooked sweet potatoes and put into a food processor. Add buttermilk, honey, salt, pepper, and nutmeg, and purée.