• Horseradish Cream Sauce: A creamy horseradish sauce adds a tangy and slightly spicy kick to complement the rich flavors of the beef. At a diner I worked at growing up, many patrons dipped the sandwich in au jus and then ranch dressing - it was actually good! • Mustard: Dijon mustard or a coarse-grain mustard provides a savory component to the sandwich. • Mayonnaise: Some people like to spread a thin layer of mayonnaise on the bread for creaminess. • Butter: Like mayo, spread butter onto the bread before preparing the French dip. • Au Jus: While it's not a condiment per se, the au jus is an essential part of the French dip experience. It's often served on the side for dipping the sandwich or poured over the top for added flavor and moisture.