Preheat your oven to 400 degrees.

In a small bowl, place the butter, 1 tablespoon of au jus mix, garlic and herb mix, Worcestershire sauce, and onion powder. Stir until well combined.

Line a baking sheet with aluminum foil. Set a loaf of bread in the center and cut it into 3/4-inch slices nearly all the way down the length of the loaf. But don't cut all the way through to the bottom, just close. Using a small spatula or butter knife, divide about 1/4 of your butter mixture evenly between each cut of the bread.

Place a folded piece of roast beef and 1/2 a piece of provolone cheese between every other cut of the bread. Make sure you don't stuff every space so you can make pull-apart sandwiches.

Spread another ¼ of the butter mixture onto the top of the bread and fold up the aluminum foil to enclose it completely. Repeat with the other loaf of bread.

Once both loaves are securely wrapped, place them in the oven on a baking sheet for about 10-15 minutes or until the cheese is thoroughly melted and the crust is crispy.

While the sandwiches are in the oven, combine the rest of the au jus gravy mix with 2 cups of water or beef stock in a small saucepan and stir. Bring to a boil, stirring often, and then bring it down to a simmer to thicken a bit until the bread is done.

Serve your herb French dip sandwiches with a bit of the au jus gravy for dipping and enjoy this hearty and flavorful supper!