Special equipment recommended, preferably a rubber spatula or a plastic dough divider.
Stir the flour and baking powder together. Cut in the cold butter until the mixture resembles coarse crumbs. Mix the fruit juice concentrate and milk together, stir in the lemon zest. Make a well in the center of the flour mixture, pour in the liquid and begin to mix together using the plastic dough divider or rubber spatula. The dough should come together forming a ball, yet remain fairly sticky, hence the need for the dough divider. This will make your task much simpler. Knead the dough a few times in the bowl until it forms a workable ball, yet retaining most of its stickiness-you may need to work in an extra tablespoon or two of flour. Put the dough down to a circle about 3/4 inch thick, wrap in plastic and refrigerate for at least one hour.
Prepare a baking sheet by sprinkling it with a generous amount of flour. Cut the dough with a serrated knife down the middle, as if you were splitting an English muffin. Place the bottom half of the scone dough on the baking sheet, lay the sliced strawberries evenly and place dollops of the jam to cover the bottom half. Lay the top of the scone dough over this and slightly crimp the edges together. You may want to carefully lift the dough at this point to check that enough flour has been sprinkled beneath it to prevent if from sticking while it bakes. If not, add a little extra.
Preheat the oven to 400°F. Cut the dough, using the dough divider or a blunt knife, into 8 equal pie-shaped wedges. Brush the top with a little milk or egg whites for a shinier appearance. Bake for 14 minutes or until browned. Serve when cooled just enough to handle, or store covered and re-heat in the toaster oven to crisp.