4 teaspoons grated lime peel plus 1/2 cup fresh squeezed lime juice (from about 4 limes)
1/2 cup unsalted butter, cut into small cubes
1/2 teaspoon peppermint extract
1 box Refrigerated Pie Crusts, softened as directed on box
Whipped cream or topping
In 2-quart nonreactive saucepan, beat 1 cup sugar, 4 eggs, 4 teaspoons grated lime peel plus 1/2 cup fresh squeezed lime juice (from about 4 limes) with whisk. Cook over medium-low heat about 10 minutes, beating constantly, until mixture is thickened.
Remove from heat; beat in 1/2 cup unsalted butter, cut into small cubes, one cube at a time, until thoroughly combined. Set mesh strainer over glass bowl; strain mixture into bowl. Stir in 1/2 teaspoon peppermint extract. Cover and refrigerate while making tart shells.
Heat oven to 425°F. From 1 box refrigerated pie crusts, softened as directed on box, unroll 1 crust on work surface. Use 3-inch round cutter to cut 7 rounds, and place on outsides of cups of upside down nonstick mini muffin pan, skipping every other one. Repeat with second crust.
Bake about 8 minutes or until golden. Cool 5 minutes; remove shells from pan to cooling rack to cool completely.
Fill each shell with cooled lime mixture. Serve immediately, or refrigerate and serve within 3 days. Top with a dollop of whipped cream or topping just before serving.