Preparation Stir pecans in heavy large skillet over medium heat until fragrant and slightly darker in color, about 2 minutes. Transfer nuts to small bowl. Melt 1 1/2 tablespoons butter in same skillet over medium heat. Add onion and sauté until golden brown, about 10 minutes. Add half of cloves and sauté 1 minute longer. Season to taste with salt and pepper. Using slotted spoon, transfer onion to plate. Melt remaining 1 1/2 tablespoons butter in same skillet over medium-high heat. Sprinkle liver with remaining cloves, salt and pepper. Add liver to skillet and sauté until brown on outside but still pink in center, about 2 minutes per side. Transfer liver to plates. Add balsamic vinegar, pecans and onion to skillet and stir 1 minute. Spoon onion mixture atop liver and serve.
Preparation Stir pecans in heavy large skillet over medium heat until fragrant and slightly darker in color, about 2 minutes. Transfer nuts to small bowl. Melt 1 1/2 tablespoons butter in same skillet over medium heat. Add onion and sauté until golden brown, about 10 minutes. Add half of cloves and sauté 1 minute longer. Season to taste with salt and pepper. Using slotted spoon, transfer onion to plate. Melt remaining 1 1/2 tablespoons butter in same skillet over medium-high heat. Sprinkle liver with remaining cloves, salt and pepper. Add liver to skillet and sauté until brown on outside but still pink in center, about 2 minutes per side. Transfer liver to plates. Add balsamic vinegar, pecans and onion to skillet and stir 1 minute. Spoon onion mixture atop liver and serve.