Creating French Dip Tortilla Roll Ups is straightforward if you follow these simple steps:

1. Prepare the Filling: In a bowl, combine the roast beef, provolone cheese, Swiss cheese, Worcestershire sauce, and Dijon mustard. Mix well until the ingredients are evenly coated.
2. Assemble the Roll Ups: Lay a tortilla flat on a clean surface. Spoon a generous amount of the filling mixture onto the lower third of the tortilla.
3. Roll the Tortilla: Starting from the bottom, carefully roll the tortilla up tightly, ensuring the filling stays secure. Repeat with the remaining tortillas and filling.
4. Heat the Pan: In a large skillet, heat the olive oil over medium heat.
5. Cook the Roll Ups: Place the roll-ups seam-side down in the skillet. Cook for about 2-3 minutes on each side or until golden brown and crispy.
6. Slice and Serve: Remove from the skillet and let them cool for a minute. Slice the roll-ups into bite-sized pieces.
7. Prepare the Dipping Sauce: In a small saucepan, heat the au jus sauce until warmed through.
8. Garnish: If desired, sprinkle the roll-ups with chopped parsley for added color.
9. Serve with Au Jus: Arrange the sliced roll-ups on a platter and serve with the warm au jus for dipping.

These steps will guide you in creating these incredible roll-ups effortlessly.