Zest lemon and set aside, then cut the lemon in half and put the juice in a bowl and set aside.

In a large mixing bowl, stir together flour, sugar, baking powder, baking soda and salt and lemon zest.

Using pastry blender or a fork, cut in the butter until the mixture is crumbly.

Add buttermilk and stir with a fork to make a very soft and sticky dough.

Pre-heat the oven to 425F.

On a lightly floured surface, place the dough and knead it a few times.

Fold in the blueberries.

Form the dough into a large round circle, about 1" thick

Cut into pie shape wedges.

Place the wedges onto parchment paper on a baking sheet.

Beat the egg in a bowl and then brush the tops of the scones with the egg.

Bake in oven for 12 to 15 minutes or until golden brown.