1 1/2 lbs. sirloin steak sliced across the diagonal very thin
salt and pepper to taste
2 T. olive oil
1/4 C. minced shallot
2 garlic cloves minced
1 t. fresh thyme
1/2 C. dry white wine
1 1/2 C. beef stock
4 french rolls
Season the beef with salt and pepper. In a large skillet, heat oil over moderately high heat. Cook the beef in batches and cook about 2 minutes, or until browned on both sides. Transfer meat to a platter and keep warm.
Add butter to skillet and melt. Add garlic, shallots and thyme and cook, stirring for 2 minutes. Add the wine and reduce by half. Add the stock and simmer for 5 minutes. Butter and toast the rolls. Drizzle some of the au jus over the meat.
Divide the meat among the 4 buns. Transfer some of au jus to dipping bowls and serve with the sandwiches.
Note: You can add fresh sliced mushrooms to this sandwich, if you choose. Saute them right after the beef.