Crostini Alla Fiorentina

Heat the oil in a skillet over low heat. Add the onion, celery, carrot and garlic; cook and stir for about 5 minutes until onions are soft. Pat the chicken and lamb liver dry, and add to the skillet. Fry over low heat until all sides are browned. Pour the red wine over the liver, and let it vaporize for a minute. Stir in the tomato puree, half of the parsley, anchovies, chicken stock, salt and pepper. Cover, and simmer for about 20 minutes. Use a hand-held blender to puree the liver mixture. If you don't have one, transfer to a food processor, and process until smooth. Return to the skillet, and stir in the butter, capers and remaining parsley.