Makes about1 qt
                    
                
                
                    
                        
                            - Active time:30 min
 
                        
                            - Start to finish:4 hr
 
                        
                    
                
             
            
            
                
                
                
    
      
          
          
          
              
              
              
          
          
          
          
          
              
              
              August 2009
            
          
          
      
  
                
                
            
            
            
                The satiny hazelnut-flavored chocolate called gianduia—named for the masked character Gianduia of the centuries-old Italian commedia dell’arte—makes for a gelato that is suave and intense. 
            
            
            
            
            
                
                    
                    
                    
                        
                            
                            
                            
                                
                                    
                                        - 
                                            2
                                            cups
                                            hazelnuts (8 oz), toasted (see Tips), skins rubbed off, and cooled
                                            
                                        
 
                                    
                                        - 
                                            3/4
                                            cup
                                            sugar
                                            
                                        
 
                                    
                                        - 
                                            1/8
                                            teaspoon
                                            salt
                                            
                                        
 
                                    
                                        - 
                                            4 1/2
                                            cups
                                            whole milk
                                            
                                        
 
                                    
                                        - 
                                            3
                                            tablespoons
                                            cornstarch
                                            
                                        
 
                                    
                                        - 
                                            
                                            
                                            bittersweet chocolate (no more than 60% cacao), finely chopped
                                            
                                        
 
                                    
                                
                            
                         
                    
                 
            
            
            
            
            
                
                    
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Equipment: 
                            
                            an ice cream maker
                         
                    
                
            
            
            
            
                
                    
                    
                    
                        
                            
                                
                                
                                
                                    
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Pulse hazelnuts with sugar and salt in a food processor until finely ground. Transfer to a heavy saucepan with milk and bring to a boil, stirring occasionally. Remove from heat and let steep, covered, 20 minutes.
                                         
                                    
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Strain mixture through a fine-mesh sieve into a bowl, then return to cleaned saucepan.
                                         
                                    
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Put 1/4 cup milk mixture in a small bowl and whisk in cornstarch. Return to saucepan, then boil over medium heat 2 minutes, whisking often (mixture will be thick). Remove from heat and add chocolate, stirring until melted and incorporated. Chill, stirring occassionally, until very cold, 3 to 6 hours.
                                         
                                    
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Freeze mixture in ice cream maker. Transfer to an airtight container and put in freezer to firm up.
                                         
                                    
                                
                             
                        
                    
                    Cooks’ note: Gelato keeps 1 week.