I make gluten free crusts for mine and they turn out pretty nom.
When I was pregnant I made lemon meringue pies from scratch several times a week and would eat the whole thing in one sitting. hahaha.
However, from scratch, there is approx. 42 g of protein PER PIE. And since I needed 72 g a day, and didn't puke them up, that's how I rationalized it.
Don't have a link because it's been tweaked quite a bit over the course of making 20+ pies over that summer. This is just for the filling and meringue because I eyeball the shell ingredients. You can just use whatever kind of dough shell.
For filling
1 cup-ish of sugar
6 tablespoons cornstarch
1/4 teaspoon salt
1 cup water
1/2-ish cup milk
5 large egg yolks
1 tablespoon unsalted butter
1/2 cup fresh squeezed lemon juice (or more, to taste. The custard should be tart!)
2 teaspoons freshly grated lemon zest
For meringue
5 large egg whites
1/4 teaspoon cream of tartar
1/2 cup sugar
Make filling:
In a heavy saucepan whisk together sugar, cornstarch, and salt and gradually whisk in water and milk, whisking until cornstarch is dissolved. In a bowl whisk together egg yolks. Cook milk mixture over moderate heat, whisking, until it comes to a boil. Gradually whisk about 1 cup milk mixture into yolks and whisk yolk mixture into milk mixture. Simmer mixture, whisking, 3 minutes. Remove pan from heat and whisk in butter, lemon juice, and zest until butter is melted. Cover surface of filling with plastic wrap.
Make meringue:
In another bowl with an electric mixer beat egg whites with cream of tartar and a pinch of salt until they hold soft peaks. Beat in sugar in a slow stream, beating until meringue just holds stiff peaks.
Pour filling into shell and spread meringue on top, covering filling completely, sealing it to pastry. Draw meringue up into peaks and bake pie in middle of oven until meringue is golden, about 15 minutes.
You can easily reduce sugar to half a cup in the custard without affecting the pie in a bad way. But NOT the meringue. It's meant to have a tart custard and sweet meringue.
Oh man, now I need to make some pie.