French Onion Stuffed Pork Loin with White Wine Dijon Sauce

Recipe Date: July 30, 2025
Difficulty: Easy
Measurements: Imperial (US)

So this one reads a little fancy but when you taste it you will understand that the final product is worth the effort.  I love anything involving a caramelized onion, and then add a Dijon sauce?!? Perfection! Especially when you pair our ‘Fifteen 10’ Red.

Ingredients

  • 6 tbsp butter
  • 2 sweet onions sliced very thin
  • 1/2 cup beef broth
  • 1 3 lb center cut pork loin
  • 2 tbsp extra virgin olive oil
  • 1 tsp Italian seasoning
  • 2 cups shredded gruyere cheese, divided
  • 1/2 cup Dijon mustard
  • 1/4 cup whole grain mustard
  • 1/4 cup dry sherry
  • 1 tsp fresh thyme leaves
  • 1 tsp cayenne pepper (optional)
  • 2 tsp salt (for marinade)
  • 3/4 tsp black pepper
  • 2 tbsp brown sugar
  • 1/2 cup water

Directions

  • Whisk together Dijon, whole grain mustard, sherry, 2 tablespoons melted butter, thyme leaves, cayenne and teaspoon salt in large bowl until combined.  Add loin to bowl and coat, cover and marinate for at least 4 hours.
  • In a large oven safe skillet over medium high heat, melt 3 tablespoons of butter.
  • Add sliced onion and beef broth and cook until tender and browned, about 20 minutes.  Adjust heat so onions do not burn.
  • Preheat oven to 350F and remove pork from marinade, reserving 3 tablespoons marinade.  Season pork on all sides with salt and pepper.
  • Butterfly pork loin (not tenderloin, different cut) by placing on a cutting board and holding a knife blade parallel to the board and carefully make a lengthwise cut about 1/3 of the way from the bottom, stopping about 1 inch from the opposite end, being careful not to cut through. Then, open the loin like a book.
  • Make a second cut on the thick side of the loin, horizontal with the first cut,  Do not cut all the way through, stop about 1 inch from the opposite edge.  Fold that edge over making one long cut of pork loin. If need be, google “how to butterfly a pork loin” for video instructions.
  • Cover with plastic wrap and pound to an even 1/3 inch thickness.
  • Add Italian seasoning, half of the onions, and half of the cheese to top side of pork loin.
  • Tightly roll the loin to completely enclose all of the filling.
  • Using twine, tightly secure the roll.
  • Using the same pan over medium heat, sear loin on all sides.
  • Transfer loin to roasting pan and roast for 30 minutes or until internal temperature registers at least 130F, more if desired. Melt remainder of cheese at the end of cooking.
  • Rest roasted loin for at least 20 minutes and make the Dijon Sauce.
  • Using the same pan again, add wine, brown sugar, thyme leaves, reserved marinade and remaining butter, and water and reduce.  Salt and pepper to taste.
  • Slice pork and top with sauce, serve with mashed potatoes and roasted Brussel spouts.  *Pro Tip – Roast the spouts in roasting pan under pork loin while cooking.  Saves time and dishes.
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