In medium saucepan over low heat, melt butter and chocolate chips. Stir constantly until well blended. Remove from heat; cool 5 minutes. Stir in marshmallows and 1 cup nuts. Do not allow marshmallows to melt. On wax paper,shape mixture into two 7" long rolls. Wrap in foil; refrigerate about 20 minutes. To coat rolls, roll in additional nuts. Wrap; refrigerate overnight. Cut rolls into 1/4" slices. Store in airtight container in cool, dry place. Makes about 3 dozen slices.