Sift the almond flour and all-purpose flour together. Add sugar and salt, and mix well.

Add butter and mix using a spatula or dough blender until the butter is broken into small pieces.

Use your hands to combine the mixture until it forms a crumbly dough.

Press 2/3 of the dough into a tart pan firmly to form the base.

Spread the blueberries evenly over the base.

Sprinkle the remaining dough over the blueberries to form the crumble topping.

Bake in a preheated oven at 180°C (356°F) for about 30 minutes.