Preheat the oven to 325°F (165°C). Line an 8-inch springform pan with baking paper at the bottom and grease the sides with a slick of butter.
In a mixing bowl combine the almond flour with the Erythritol and melted butter to make a dough. Transfer into the prepared baking pan and press with your fingers to create a solid base. Refrigerate for 15-20 minutes to set.
In the meantime, with a blender or whisker, combine the cream cheese with the powdered Erythritol, sour cream, lemon zest, vanilla extract, and liquid Erythritol. Add the eggs one at a time, until fully incorporated into the mixture. Finally, fold in the almond flour.
Pour into the pan above the crust.
Bake for 45 minutes until the sides are golden but the center is still springy. Let it cool for 20 minutes in the oven with the oven door open.
Remove from the oven and let it cool down completely while you prepare the sauce.
In a saucepan combine the strawberries with the water, lemon juice and Erythritol. Bring to a gentle simmer. Add the xanthan gum and let it simmer for a few minutes until the sauce thickens.
Remove the saucepan from the heat and allow it to reach room temperature. Pour the sauce evenly over the cheesecake.
Slice and serve cold.