Place chicken broth and garlic in a small saucepan and bring to a boil over high heat, cover; reduce heat to low and simmer 25-30 minutes. or until garlic mashes easily with a fork. Set aside to cool and then puree until smooth in a blender or food processor.
Heat olive oil in a large, non-stick skillet over medium-high heat. Add the pork and cook 1 to 1 1/2 minutes on each side or until browned.
Pour the garlic puree into the skillet and sprinkle with the parsley, tarragon, salt and pepper. Bring to a boil; cover. Reduce heat to low; simmer 15-20 minutes until pork is juicy and barely pink in center. Remove pork from skillet and keep warm.
Combine flour and water in a small cup and slowly pour into skillet; bring to a boil. Cook, stirring, until mixture thickens. Stir in sherry.