Preheat your oven to 325 degrees f.
Place the ghee/butter in a microwave-safe bowl or a small pot on the stovetop and melt until just warm and melted.
Take about 1 Tablespoon of your melted ghee and using your fingertips or a pastry brush, grease a 9-inch tart pan.
Beat egg white until frothy.
Add your honey and vanilla to a bowl with the remaining melted ghee/butter, and stir well to combine.
In a large bowl, combine the oats, seeds, and coconut. Pour in your ghee-honey mixture using a spatula to get all of it and add your beaten egg white then thoroughly stir to combine.
Press this mixture into your prepared tart pan, going all up the sides to create the crust.
Bake the crust for around 22-25 minutes in your preheated oven or until it is just golden brown and holds its shape.
Allow your crust to completely cool.
Meanwhile, in a large bowl, whisk all the filling ingredients together.
Carefully transfer the tart crust onto a platter.
Gently pour in your yogurt filling and smooth evenly with a spatula.
Top with fresh berries and lemon zest, as desired.
Serve immediately and enjoy!