Preheat oven to 375°.
Roll out and press crust into pie plate.
Crimp edges and then put in refrigerator.
Boil sweet potatoes in salted water for 10 minutes (not completely cooked through), drain and cool.
Cook bacon in sauté pan until half done.
Remove bacon and set aside in medium sized mixing bowl.
Drain off most of the fat from the pan and return to medium heat.
Add chopped onion and cook until clear (5-7 minutes).
Add cooked onions to the bowl with bacon and let cool.
In another bowl beat eggs with yogurt.
Add maple syrup and 1 cup of the cheese.
Add nutmeg and salt and pepper to taste.
Add bacon and onions into yogurt mixture.
In your chilled piecrust, layer sweet potatoes and yogurt mixture and cover with remaining 1/2 cup of cheese.
Bake for 30-35 minutes.