BLENDER BEARNAISE SAUCE RECIPES

Steps:

• Preheat oven to 400 degrees F. 
• Take the beef tenderloin and drizzle with olive oil. Season well all over with plenty of kosher salt and freshly ground black pepper all over. Make sure it is at room temperature before cooking. Place a large cast iron skillet over medium-high heat on the stove top and sear tenderloin all over. Place the whole pan in the oven and roast the tenderloin for 15-17 minutes (depending on how thick your tenderloin is). An instant-read thermometer when inserted into the thickest part of the meat should read 130 degrees F for medium-rare. If you want it medium, cook for a further 3 minutes in the oven. Remove from the oven and tent with foil while you let it rest for 10 minutes before cutting.
• Make the bearnaise reduction first. In a small saucepan, combine half of the tarragon, shallots, vinegar and wine over medium-high heat. Bring to a simmer and cook until reduced by half. Remove from heat and set aside to cool. 
• Blend yolks and bearnaise reduction together in a blender. With the blender running, add 1/3 of the butter in a slow steady stream. Once it emulsifies, turn the blender speed up to high and add the remaining butter. Add the remaining half bunch of fresh tarragon leaves, season with salt and pepper and give it 1 more buzz. Set aside in a warm spot to hold the sauce.

Steps:

• For the sauce, put the Champagne vinegar, white wine, shallots, 1 tablespoon tarragon leaves, 1/4 teaspoon salt, and 1/4 teaspoon pepper in a small saucepan. Bring to a boil and simmer over medium heat for about 5 minutes, until the mixture is reduced to a few tablespoons. Cool slightly.
• Place the cooled mixture with the egg yolks and 1 teaspoon salt in the jar of a blender and blend for 30 seconds. With blender on, slowly pour the hot butter through the opening in the lid. Add the remaining 2 tablespoons of tarragon leaves and blend only for a second. If the sauce is too thick, add a tablespoon of white wine to thin. Keep at room temperature until serving.
• Season the steaks liberally with salt and coarsely ground black pepper on both sides. Heat a thin layer of olive oil in a large saute pan over high heat until it's almost smoking, then sear the steaks on each side for 1 minute. Lower the heat to low and cook the steaks for about 7 to 10 minutes, turning once, until very rare in the middle. Remove to a plate, cover tightly with aluminum foil and allow to sit for 10 minutes. Serve with the bernaise sauce on the side.
• Note: To make the sauce in advance, prepare an hour before serving and allow it to sit in the blender. Before serving, add 1 tablespoon of the hottest tap water and blend for a few seconds.