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A close-up of a delicious French Onion Beef Sloppy slider, featuring tender meat, caramelized onions, and rich gravy on a soft bun, garnished with parsley.
Daniel

French Onion Beef Sloppy Joes

This recipe takes the comforting flavors of classic French Onion soup and combines them with hearty ground beef to create an incredibly flavorful and satisfying sloppy joe filling. It's a gourmet twist on a family favorite, perfect for a cozy weeknight meal.
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Prep Time 20 minutes
Cook Time 1 hour
Total Time 1 hour 20 minutes
Servings: 6 servings
Course: Main Course
Cuisine: American, French-Inspired
Calories: 610
Ingredients Equipment Method Notes

Ingredients
  

For the French Onion Beef Filling
  • 2 tbsp Unsalted Butter
  • 1 tbsp Olive Oil
  • 3 large Yellow Onions thinly sliced
  • 1.5 lbs Ground Beef 80/20 lean
  • 4 cloves Garlic minced
  • 0.5 cup Dry Red Wine e.g., Merlot or Cabernet Sauvignon, optional
  • 2 cups Beef Broth low sodium
  • 1 tbsp Worcestershire Sauce
  • 1 tsp Fresh Thyme chopped, or 1/2 tsp dried
  • 1 Bay Leaf
  • 0.75 tsp Salt or to taste
  • 0.5 tsp Black Pepper freshly ground, or to taste
For Serving
  • 6 oz Gruyere Cheese shredded
  • 6 Hoagie Buns or Brioche Buns split

Equipment

  • Large Dutch oven
  • Chef's Knife
  • Cutting board
  • Wooden Spoon

Method
 

Caramelize the Onions
  1. In a large Dutch oven or deep skillet, melt butter with olive oil over medium-low heat. Add the thinly sliced yellow onions and a pinch of salt. Cook, stirring occasionally, for 35-45 minutes, or until the onions are deeply golden brown and caramelized. This slow process is key to developing their sweet, rich flavor. Remove the caramelized onions from the pot and set aside.
Brown the Beef
  1. Increase heat to medium-high. Add the ground beef to the same pot, breaking it up with a wooden spoon. Cook until thoroughly browned, about 6-8 minutes. Drain off any excess fat.
Assemble and Simmer the Sloppy Mix
  1. Add minced garlic to the browned beef and cook for 1 minute until fragrant. If using, pour in the red wine and scrape up any browned bits from the bottom of the pot (deglazing). Let the wine reduce by half, about 2-3 minutes.
  2. Return the caramelized onions to the pot with the beef. Stir in the beef broth, Worcestershire sauce, fresh thyme, bay leaf, salt, and black pepper. Bring the mixture to a simmer, then reduce heat to low, cover, and let it cook for 15-20 minutes, allowing the flavors to meld and the sauce to thicken slightly. Remove the bay leaf before serving.
Prepare for Serving
  1. While the sloppy joe mix is simmering, preheat your oven broiler to high. Place the split hoagie or brioche buns cut-side up on a baking sheet. Broil for 1-2 minutes until lightly toasted.
  2. Spoon a generous amount of the French Onion Beef Sloppy mix onto the toasted bun bottoms. Top with shredded Gruyere cheese. Place the buns back under the broiler for 1-2 minutes, or until the cheese is bubbly and lightly golden.
  3. Place the top bun on each sandwich and serve immediately.

Notes

For the best caramelization, ensure your heat is low and be patient with the onions. You can substitute the red wine with an equal amount of additional beef broth if preferred. Store leftover sloppy mix in an airtight container in the refrigerator for up to 3 days. Reheat gently on the stovetop or in the microwave.