Instructions

• Bake the tart shell according to the package or recipe directions and cool.
  
• Whisk the eggs, egg yolks, sugar, lemon juice, lemon zest, and salt in a saucepan.
  
• Cook over medium-low heat, stirring constantly, until thickened.
  
• Remove from the heat.
  
• Whisk in the butter one piece at a time.
  
• Strain the filling into the cooled tart shell.
  
• Smooth the top.
  
• Refrigerate for at least 3 hours, or until set.
  
• Dust with powdered sugar before serving if desired.