This is a great way to use up leftover beef. I've never been able to get the onions crispy, they turn out more like caramelized onions. But still very good. From Gourmet magazine.
- 1 cup onion, thinly sliced
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- 3⁄4 cup mushroom, thinly sliced
- 1 garlic clove, minced
- 3⁄4 cup beef broth
- 1 1⁄2 tablespoons heavy cream
- 3 tablespoons ketchup
- 1 1⁄2 tablespoons Worcestershire sauce, to taste
- 1 teaspoon Dijon mustard
- 1 lb steak, grilled, cut into 1/8-inch slices
- 1 loaf Italian bread, halved horizontally and each half buttered lightly, cut into 4 pieces, toasted
- In a skillet cook the onions in the butter and the oil over moderate heat, stirring occasionally, until they are crisp and golden and transfer them with a slotted spoon to paper towels to drain.
- In the fat remaining in the skillet cook the mushrooms and the garlic over moderately low heat, stirring occasionally, until the mushrooms begin to turn brown and transfer the mixture to a plate.
- Add the broth to the skillet and deglaze the skillet, scraping up the brown bits.
- Add the cream, the ketchup, the Worcestershire sauce, and the mustard and stir in the mushroom mixture and the steak slices.
- Divide the steak mixture among the bottom bread pieces, sprinkle it with some of the onions, and top the onions with the remaining bread pieces.