Lemon Meringue Pie with sweet, smooth, melt in your mouth meringue

Ingredients

• 1 Prepared Tart Shell
• 1 cup granulated sugar
• 4 large eggs
• 2 large egg yolks (reserve whites for meringue)
• ½ cup fresh squeezed lemon juice (strained)
• ⅔ cup unsalted butter (cut into cubes and at room temperature)
• 4 large egg whites (at room temperature)
• ½ cup granulated sugar
• ⅛ teaspoon cream of tarter