8 slices white bread
1/4 c. unsalted butter, melted
16 c. slices provolone cheese (about 10 oz.)
1 c. slices thinly sliced deli roast beef (about 12 oz.)
1 c. French's Fried Onions
4 tbsp. French’s Classic Yellow Mustard
For the au jus:
1 tbsp. unsalted butter
1 clove garlic, minced
1/2 tsp. dried thyme leaves
1 1/2 c. low-sodium beef broth
1 tbsp. French’s Classic Yellow Mustard
1 tbsp. Worcestershire sauce
Kosher salt
Freshly ground black pepper
1 tbsp. freshly chopped chives
Build the sandwiches: Arrange slices of bread in a single layer on a work surface. Brush the top sides of each piece of bread with the butter. Flip the bread so the butter side is face down on the surface. Top each piece of bread with 2 pieces of provolone cheese. Top half of the slices of bread with a layer of roast beef and drizzle with mustard. Sprinkle with french onions. Sandwich with the remaining pieces of bread with the provolone side in the sandwich and butter side facing out. Heat a large skillet over medium-low heat. Place 2 sandwiches in the skillet and cook until the bottom slice of bread is golden and the cheese is starting to melt, about 5 minutes. Carefully flip the sandwich and cook until golden underneath, about 5 minutes more. Repeat with remaining sandwiches. Meanwhile, make the au jus: Melt the butter in a medium skillet over medium heat. Stir in garlic and thyme; cook until fragrant, 1 to 2 minutes. Whisk in the beef broth, mustard, and Worcestershire sauce. Increase heat to high and bring to a boil. Season with salt, if necessary and pepper. Remove from heat and keep warm. Sprinkle the au just with chives and serve the hot sandwiches sliced with the warm au jus.