Filet Mignon In Mustard Sauce

In a small bowl, whisk the mustard and heavy cream until well blended. In another small bowl, blend the 1 teaspoon butter with the flour to form a smooth paste.
In a large skillet, melt 3 tablespoons of the butter with the olive over high heat. When the foam subsides, add the steaks and sauté until well browned, about 1 1/2 minutes per side.
Reduce the heat to medium-high and season the meat with the salt and coarsely ground pepper. Cover and cook for about 4 minutes longer on each side for medium-rare. Remove the steaks to a plate. Discard all the fat from the skillet, add the remaining 2 tablespoons butter and melt over medium heat.

Reduce the heat to moderate and return the steaks to the sauce and simmer just until heated through, about 1 minute. Transfer the steaks to a warmed serving platter and top with the sauce. Garnish with the parsley and serve at once.