My wife found this online. We've also made it with red wine instead of cognac. Very tastey stuff. A regular onion can be using in place of shallots if needed. We also used actual medallions from the store, so we didn't bother slicing and fanning at the end.
When done with red wine, its kind of similar to Steak Diane from the Cheesecake factory.
Its beef...so it goes well with beer
BEEF MEDALLIONS WITH COGNAC SAUCE
2 tablespoons (1/4 stick) unsalted butter
1/4 cup chopped shallots
1 teaspoon (packed) brown sugar
1 cup canned low-salt chicken broth
1/2 cup canned beef broth
1/2 cup Cognac or brandy
1/4 cup whipping cream
2 4- to 5-ounce beef tenderloin steaks (each about 1 inch thick)
Melt 1 tablespoon butter in heavy medium saucepan over medium heat. Add shallots and sauté until tender, about 4 minutes. Add brown sugar; stir 1 minute. Add chicken broth, beef broth and Cognac. Simmer until sauce is reduced to 1/2 cup, about 20 minutes. Add cream. (Can be made 1 day ahead. Cover; chill.)
Sprinkle steaks with salt and pepper. Melt 1 tablespoon butter in heavy medium skillet over medium-high heat. Add steaks; cook to desired doneness, about 4 minutes per side for rare. Transfer steaks to plates. Add sauce to skillet; bring to boil, scraping up any browned bits. Season to taste with salt and pepper.
Slice steaks; fan slices on plates. Top with sauce and garnish with chives.