Rinse and dry all herbs. If thyme stems are woody, remove the leaves and discard the stems. Chop parsley, chives, scallions, celer,y and cilantro coarsely. Place all ingredients in bowl of food processor or high-speed blender and process to a smooth, thick paste. If necessary, add up to ½ cup of water, 1 tablespoon at a time, to facilitate processing.