Boil livers with salt, covered, for 20 minutes, or until tender. Drain, put through food chopper, using fine chopper. (Some spices, particularly mustard, can be lumpy.) To insure equal distribution of spices, mix all dry and liquid ingredients together, dissolving any existing lumps in the dry spices. When completely homogenized, mix with the chopped liver and butter. Blend thoroughly and chill. Use as a spread on toast or crackers.