Bright, tangy, and velvety smooth, this healthy twist on a classic bakery favorite brings together a golden almond-flour crust, a zesty sugar-free lemon curd,

Equipment

• 9-inch pie dish: Provides even heat distribution to ensure the almond-flour crust bakes to a golden, sturdy finish.
• Stand mixer or electric hand mixer: Rapidly whips egg whites into stable, glossy stiff peaks without manual fatigue.
• Fine-mesh strainer: Catches any stray cooked egg bits from the warm curd to guarantee an ultra-smooth filling texture.
• Zester/microplane: Extracts fragrant lemon oils from the peel without picking up the bitter white pith.
• Silicone spatula: Gently folds and seals the meringue all the way to the pie crust edges to prevent shrinking.

Ingredients

• 1 ½ cups blanched almond flour (fine grind works best for a smooth crust)
• 3 tbsp unsalted butter, melted (or coconut oil)
• 2 tbsp granulated monk fruit/erythritol blend
• 1 pinch fine sea salt
• 1 large egg yolk (reserve the white for meringue)

• ½ cup fresh lemon juice (strained; requires about 3–4 medium lemons)
• 1 tbsp fresh lemon zest (finely grated)
• ⅓ cup granulated monk fruit/erythritol blend (adjust slightly to taste)
• 3 large whole eggs + 2 egg yolks (reserve whites for meringue)
• ⅓ cup unflavored whey protein isolate (ensure it is 100% pure isolate without added gums)
• 3 tbsp unsalted butter, diced into small cubes
• ½ tsp xanthan gum (for a thick, sliceable set without cornstarch)

• 3 large egg whites (room temperature)
• ¼ tsp cream of tartar (critical for stabilizing the egg whites)
• ⅓ cup powdered monk fruit sweetener (dissolves cleanly without grit)
• ½ tsp pure vanilla extract

Instructions

1. Blind-Bake the Crust: Preheat the oven to 350°F (175°C). In a medium bowl, mix the almond flour, melted butter, 2 tablespoons sweetener, salt, and 1 egg yolk until a crumbly dough forms. Press the mixture firmly across the bottom and up the sides of a greased 9-inch pie dish. Prick the base lightly with a fork and bake for 10–12 minutes until lightly golden. Remove and set aside to cool slightly.
2. Whisk Curd Ingredients: In a medium heat-safe bowl, vigorously whisk together the 3 whole eggs, 2 yolks, fresh lemon juice, lemon zest, ⅓ cup sweetener, and xanthan gum until completely smooth and frothy.
3. Thicken Over Gentle Heat: Place the bowl over a saucepan of gently simmering water (double boiler) set to medium-low heat. Stir continuously with a silicone spatula for 8–10 minutes until the mixture thickens to a custard consistency that coats the back of a spoon (internal temperature should hit ~165°F/74°C).
4. Incorporate Protein & Butter: Remove the curd from the heat. Whisk in the unflavored whey protein isolate in small batches until completely dissolved and lump-free. Stir in the cubed butter one piece at a time until melted, glossy, and emulsified. Strain through a fine-mesh sieve directly into the pre-baked crust, smoothing the top. Keep warm while preparing the topping.
5. Whip the Meringue: In a clean, grease-free glass or metal bowl, beat the 3 room-temperature egg whites and cream of tartar on medium-high speed until soft peaks form (about 2–3 minutes). Gradually sprinkle in the powdered sweetener one tablespoon at a time, followed by the vanilla extract, beating continuously on high until stiff, glossy peaks form that stand straight when beaters are lifted.
6. Mound and Seal: Spoon the meringue immediately over the warm lemon filling. Use an offset spatula to spread the meringue completely to the edges of the crust, ensuring it touches and seals against the pastry wall to prevent shrinking. Create decorative peaks by gently pressing down and lifting the spatula.
7. Bake to Golden: Place the assembled pie in the oven at 350°F (175°C) for 10–12 minutes, watching closely until the meringue peaks turn a rich amber brown.
8. Cool and Chill: Transfer the pie to a wire rack to cool completely to room temperature (about 1 hour), then refrigerate for at least 2 hours to allow the protein curd to set firmly for clean slicing.

Nutrition

Calories: 210 kcal · Protein: 14 g · Fat: s: 15 g Cholesterol: 145 mg · Carbohydrates: 6 g · Fiber: 2 g · Sugar: 1 g · Sodium: 95 mg