Preheat oven to 350°.
Cut the bacon in quarters and put it and the and mustard in a food processor and puree until a smooth paste consistency. Coat scallops with puree. Using a frying pan, sear the scallops in a little oil. Place scallops in the oven and bake for 8 to 10 minutes. Remove scallops and allow to rest for 2 minutes before serving. Place creme fraiche mashed potatoes on each of 4 plates and top each with 4 scallops.
Creme Fraiche Mashed Potatoes:
Prepare the creme fraiche ahead of time by combining 1 cup of the heavy cream with 1/2 cup of the sour cream, cover with plastic wrap and let stand at room temperature for 12 to 24 hours. Stir well and refrigerate for 4 hours.
Place the potatoes in a pot, cover with cold water, and add salt. Bring to a boil and cook potatoes for 20 to 25 minutes, and drain. With an electric mixer, beat the potatoes with the cream cheese, the remaining sour cream, and 2 tablespoons of heavy cream, garlic, house seasoning, and seasoned salt. Stir in the butter and onions. Place the mashed potatoes in a lightly greased 2-quart round casserole, spoon the creme fraiche on top, and sprinkle with chives. Bake until potatoes are hot, approximately 20 to 30 minutes.