Common Persian limes—the ones usually found in the grocery store—will work in this recipe, but Key limes are preferred in this tangy pie.

Makes 8 servings

ACTIVE TIME: 50 minutes

TOTAL TIME: 8 hours (includes chilling time)

EASE OF PREPARATION: Easy

Graham-Cracker Crust
1 large egg white
1 1/4 cups graham cracker crumbs (12 crackers)
1 1/2 tablespoons butter, melted
1 1/2 tablespoons canola oil

Filling
1 14-ounce can sweetened condensed milk
2/3 cup low-fat plain yogurt
2 teaspoons freshly grated Key lime zest
1/2 cup Key lime juice (4 to 5 limes)
1 1/2 teaspoons unflavored gelatin
2 tablespoons cold water

Meringue
2/3 cup sugar
1/2 cup water
2 large egg whites, at room temperature (see Tip)
1/4 teaspoon cream of tartar
1 teaspoon vanilla extract
Key lime slices for garnish

1. To make crust: Preheat oven to 350°F. Coat a 9-inch pie plate with cooking spray.
2. Beat 1 egg white lightly with a fork in a medium bowl until frothy. Add graham cracker crumbs, butter and oil and blend with your fingertips until thoroughly combined. Press the mixture in an even layer on the bottom and sides of the prepared pie plate. Bake until lightly browned, about 10 minutes. (Do not be concerned if there are small cracks.) Cool on a rack.
3. To make filling: Whisk together sweetened condensed milk, yogurt, lime zest and juice in a medium metal bowl. Sprinkle gelatin over cold water in a small saucepan. Let soften for 1 minute. Heat over low heat, stirring, until the gelatin is dissolved. Whisk into the lime mixture. Set the bowl over a larger bowl of ice water, stirring occasionally, until it begins to thicken, 15 to 20 minutes. Turn into the pie shell and chill in the refrigerator while you prepare the meringue.
4. To make meringue: Preheat the broiler. Combine sugar with water in a small saucepan. Bring to a boil, stirring occasionally. Cook over medium-high heat, without stirring, until the syrup registers 240°F and is at the soft-ball stage (when a bit of syrup dropped into ice water forms a pliable ball), about 5 minutes. Remove the syrup from heat. Set aside.
5. Beat 2 egg whites in a large bowl with an electric mixer on medium speed until frothy. Add cream of tartar and beat on high speed just until soft peaks form. Return the syrup to the heat until it boils. Gradually pour the hot syrup into the egg whites but not directly onto the beaters, beating constantly. Continue beating until the egg whites are cool and very stiff, about 5 minutes. Blend in vanilla.
6. Remove the pie from the refrigerator and spread the meringue over top, sealing to the edge of the crust and swirling roughly on top. Place the pie under the broiler for 1 to 2 minutes, or until lightly browned. Let cool to room temperature, then refrigerate until the filling has set, for 5 to 8 hours. Garnish with Key lime slices just before serving.

NUTRITION INFORMATION: Per serving: 329 calories; 6 g fat (2 g sat, 2 g mono); 13 mg cholesterol; 60 g carbohydrate; 8 g protein; 0 g fiber; 167 mg sodium; 591 mg potassium.
Nutrition bonus: Potassium (17% daily value), Calcium (17% dv).
4 Carbohydrate Servings
Exchanges: 1/2 starch, 1 1/2 fat-free/low-fat milk, 1 other carbohydrate, 1 fat

TIP: Tip: To bring an egg to room temperature: Either set it out on the counter for 15 minutes or submerge it (in the shell) in a bowl of lukewarm (not hot) water for 5 minutes.

This is the best pie ever! I've made it with both key and persian limes. Tip... i pull out my Betty Crocker book to make the meringue.

Jane, Tacoma, WA