Preheat oven to 375 degrees. Grease 2 ten ounce ramekins or gratin dishes with shortening. Combine the flour,sugar,baking powder and salt in a small bowl. Stir in the lemon juice, milk and butter just until incorporated. Place half the blueberries into the greased baking dishes. Divide the batter between the two dishes and top with the remaining blueberries. Sprinkle with raw sugar for a slight crunch if desired. Bake at 375 degrees for 25 to 30 minutes or until golden brown.