Roast fillet of beef: In a heavy flameproof roasting pan heat the oil over moderate high heat until it is hot but smoking, add the beef, patted dry and seasoned with salt and pepper, and brown it, turning it every 2 minutes, for 10 minutes. Roast the beef in a preheated 500 degree oven for 12 to 15 minutes, or until a meat thermometer registers 130 degrees. The narrow end of the beef will be medium-rare; the wide end will be rare. Serve the beef with the sauces.
Red pepper sauce: In a heavy skillet cook the bell peppers in the oil, covered, over moderately low heat, stirring occasionally, for 25 to 30 minutes, or until they are soft. In a blender puree the mixture with the chipotle, the Worcestershire sauce, and salt to taste. The sauce may be made 2 days in advance and kept covered and chilled. Transfer the sauce to a sauceboat and serve it warm or at room temperature.
Mustard chive sauce: In a small bowl stir together the mustard, the vinegar, the sugar, the salt, and 3 tablespoons water, making a smooth paste, and let the mixture stand, covered, for 10 minutes. Transfer the mixture to the top of a double boiler set over barely simmering water and whisk in the butter until it is just melted and incorporated thoroughly. Remove the pan from the heat and stir in the chives. Transfer the sauce to a sauceboat and serve it warm or at room temperature.
Recipe courtesy of Gourmet Magazine