Pork Tenderloin with Caramelized Onions, grapes and Old-Fashioned Mustard

From: Amelie Wine Bar, New York City. Yield: 4 servings.

1 large yellow onion, cut into ½” thick slices
6 Tbsp. butter
½ lb. pork tenderloin, cut into ½” thick slices
to taste, salt and freshly ground black pepper
1 tsp. paprika
1 cup Sancerre or other dry wine
2 cups chicken broth
4 tsp. whole grain mustard
16 seedless red grapes, halved
as needed, mashed potatoes
4 sage leaves, minced

In large skillet, cook onion in 1 Tbsp. butter until caramelized, about 8 minutes. Remove from pan. Dust pork with salt, pepper and paprika. Melt 1 Tbsp. more butter in pan and sear pork 1 minute per side. Remove from pan.

Add remaining 4 Tbsp. butter, wine and broth; heat until butter is melted. Stir in onions and mustard and simmer about 10 minutes to reduce it. Add grapes; heat 30 seconds then add pork. Heat just until warmed, about 30 seconds. Serve on mashed potatoes; sprinkle with sage.