Heat olive oil in medium skillet over medium high heat. Lightly flour liver and place in pan and sear for 5 seconds and flip. Add arugula and garlic and quickly saute Deglaze with balsamic vinegar and serve over onion tart, recipe follows.
For the Tart: Render diced bacon until crispy. Add butter, onion, rosemary and cook until tender. Season with salt and pepper. Roll out dough and plate filling in middle and top with blue cheese. Fold over edges and bake in a preheated 500 degree oven until golden brown, approximately 10 to 12 minutes. Serve with calves liver.
Recipe courtesy of Michael Symon, Lola, Cleveland