Pan-Seared Tenderloin with Bearnaise Sauce
1 tablespoon olive oil
4 beef tenderloin steaks, about 1 1/2 inches thick (4 ounces each)
1/2 cup chopped onion
2 tablespoons white vinegar
2 tablespoons white wine
1/4 teaspoon dried tarragon
2 egg yolks
1/4 cup (1/2 stick) butter
1 teaspoon lemon juice
1/4 cup half and half
Preheat oven to warm, about 200 degrees F.
Heat oil on medium heat in an extra-deep, 12-inch, nonstick skillet. Add steaks and begin to cook until medium-rare, about 5 to 6 minutes per side (or until desired doneness). Remove to a plate and keep warm in the oven.
Meanwhile, peel and finely chop onion. In a small (1-quart) saucepan, add onion, vinegar, wine and tarragon and bring to a boil over high heat. Continue to boil for about 2 minutes until only about 1 teaspoon of liquid remains. (Be sure to let enough liquid evaporate and watch it carefully during the final minute. It will evaporate quickly.) Set aside.
Make sauce: Separate egg yolks into a small bowl and beat well with a fork. Put butter in a 2-cup glass measure and microwave on high until melted, about 45 seconds. Remove butter from microwave and stir until completely melted. Stir yolks, lemon juice and half and half into melted butter. Microwave mixture on high, uncovered, for 1 minute stirring every 15 seconds with a fork. When done, sauce will be just slightly thick. Remove from microwave and stir in the reserved onions with remaining liquid.
Pour 1/4 cup sauce over each steak. Serve at once.