1/4 lb. medium sized mushrooms
1 lg. or 2 med. sized tomatoes
butter
1 lg. onion, cut into 3/4 inch thick slices
4 beef tenderloin (filet mignon) each 1 inch thick
1/2 c. water
2 tbsp. prepared mustard
4 tsp. capers, drained
Watercress sprig for garnish

If you like flute mushrooms, set aside. Cut four thick center slices from tomatoes; reserve any leftover tomatoes to use in salad another day. In 10 inch skillet over medium heat, in 1 teaspoon hot butter, cook tomatoes until heated through. Remove to warm platter. Meanwhile in 12 inch skillet over medium heat; in 2 tablespoons hot butter cook onion until tender, stir occasionally. Remove to bowl. In drippings remaining in skillet over medium high heat, cook mushrooms and tenderloin steaks about 5 minutes for rare or until of desired doneness turning steaks once. Remove steaks and mushrooms to platter, placing one steak on each tomato slice; keep warm. Into drippings remaining in skillet, stir water, mustard, and capers; over medium heat cook, stirring constantly, until mixture thickens slightly and boils. Return onions to skillet; heat through. Pour sauce over and around steaks. Garnish platter with watercress sprigs.