Slice in the cold butter and blend with a pastry blender till the mixture is like a coarse meal texture. (You may use two knives and "cut" the butter in by slicing in an "X" pattern if you don't have a pastry blender.).
Pour the squeezed lemon juice in a measuring cup.
Crack the egg in the measuring cup with the lemon juice.
Pour in enough milk into the SAME measuring cup until you have about 1 cup of liquid total.
Gently mix the wet and dry ingredients.
Mix in the blueberries.
Knead the dough on floured board 4 to 5 times and pat out to about 1" thick.
Cut with cookie cutter or slice into triangles and place on greased cookie sheet.
Bake for 12-15 minutes or until done.
*You may sprinkle sliced almonds on before baking*.