1. Preheat your oven to 175°C.

2. In a mixing bowl, combine almond flour, coconut flour, and powdered erythritol for the crust. Add melted butter and mix until well combined.

3. Press the crust mixture into a pie dish, making sure to evenly distribute it on the bottom and up the sides. Bake for about 10 minutes until lightly golden. Remove from the oven and let it cool.

4. In a saucepan, whisk together eggs, lemon juice, lemon zest, powdered erythritol, and heavy cream for the filling. Place the saucepan over medium heat and cook while stirring constantly until the mixture thickens.

5. In a separate small bowl, sprinkle gelatin over ¼ cup of cold water and let it bloom for a few minutes. Then, gently heat the gelatin mixture until it dissolves completely.

6. Remove the lemon mixture from heat and stir in the dissolved gelatin. Let it cool for a few minutes.

7. Pour the lemon filling into the cooled crust and refrigerate for at least 2 hours or until set.

8. In a clean mixing bowl, beat egg whites and cream of tartar until soft peaks form. Gradually add powdered erythritol while continuing to beat until stiff peaks form.

9. Preheat your broiler. Spread the meringue over the chilled lemon filling, making sure to seal the edges. Place the pie under the broiler for about 2-3 minutes until the meringue is lightly browned.

10. Remove from the oven and let it cool before serving. Enjoy your Keto Lemon Meringue Pie!

Note: It’s important to keep in mind that erythritol can have a cooling effect, so adjust the sweetness according to your taste preferences.