When is it done? Custard pies should be removed from the oven before the center is completely set. The center will jiggle slightly when dish is gently shaken. Filling will continue to cook after it's removed and the center will firm up quickly.
For neat slices, dip knife into glass of water, letting excess water drip off, before each cut. This prevents the meringue from sticking to knife and tearing it. Be sure to cut completely through the crust.
A hot filling is important. The heat of the filling cooks the bottom of the meringue and prevents it from weeping and creating a slippery layer between filling and topping. Set up your equipment and measure meringue ingredients before you make the filling and work quickly to make meringue before filling cools.
To check if sugar is dissolved, rub a bit of meringue between your thumb and forefinger. If sugar is dissolved, it will feel completely smooth. If it feels grainy, continue beating.
What's a soft peak? To check for soft peaks, stop the mixer and lift the beater. The peaks left in the meringue should curl at the tips. If the peaks stand straight and tall (stiff peaks), the meringue has been overbeaten.
Anchor the meringue. Be sure to attach the meringue to the crust all around the edge of the pie. This prevents the meringue from pulling away from the edge during baking.
Beads may form on meringue when refrigerated; gently touch beads with tip of paper towel to absorb.
Refrigerate any leftover pie promptly.
For the filling:
- Pre-made pie dough
- 1 ¼ Cup sugar
- ½ Cup all-purpose flour
- 5 egg yolks, well beaten
- ¾ Cup half-and-half
- 1 Teaspoon vanilla extract
- 2 Cups sliced fresh or frozen rhubarb
- 1 Cup sliced strawberries
For the meringue:
- 1 Tablespoon cornstarch
- 1/3 Cup cold water
- 5 egg whites, at room temperature
- ¼ Teaspoon cream of tartar
- ½ Cup sugar
- ½ Cup vanilla extract
For the filling:
Preheat the oven to 425 degrees F.
Roll the pie dough out and fit into a 9-inch pie pan.
Mix the sugar and flour in a medium bowl. Whisk in the egg yolks, half-and-half, and vanilla; beat until blended. Gently fold in the rhubarb and strawberries. Pour the mixture into the crust.
Place the pie on rack in the center of the oven and bake for 15 minutes.
Reduce heat to 350 degrees F and continue baking until almost set, 25 to 30 minutes; the center will jiggle slightly. Cool on wire rack 5 to 10 minutes.
For the meringue:
Dissolve the cornstarch in the cold water in a 1-cup glass measure. Microwave the mixture on high for 30 seconds; stir. Microwave until the mixture boils, 15 to 30 seconds longer. Remove; cover.
Beat the egg whites and cream of tartar in a mixer bowl fitted with a whisk attachment on high speed until foamy. With the mixer running, add the sugar, 1 tablespoon at a time, beating after each addition until the sugar dissolves before adding the next spoonful. Continue beating until the whites are glossy and stand in soft peaks. With the mixer still running, add the cornstarch paste, 1 to 2 tablespoons at a time. Then beat in the vanilla.
Quickly spread the meringue evenly over the filling, starting at the edge and sealing to the crust all around; swirl with back of spoon. Bake in upper third of the oven until lightly browned, 15 to 17 minutes. Cool on a wire rack for 1 hour, then refrigerate for 3 to 4 hours before serving.