For the Shortbread Biscuits:
1. Preheat oven to 450 degrees.
2. Whisk together dry ingredients and then grate the butter (if frozen) or cut cold butter into small cubes and using your fingers, mix into the dry ingredients quickly and evenly.
3. Pour in milk and stir quickly with the handle end of a wooden spoon just until the dough comes together.
4. Sprinkle a little flour onto a work surface, and pat out dough into a circle, about one and one half inches thick. Cut into 4 or 6 wedges and place on a baking sheet that has been lightly greased.
5. Brush wedges with the 2 tbsp of milk and sprinkle with course sugar.
6. Bake for 12 minutes or so, until tops are golden.
For the Strawberry-Rhubarb Com
1. Put rhubarb into a small pot with the brown sugar. Add a splash of water and bring to a simmer vigorously, until the rhubarb softens and thickens, about 10 minutes.
2. Toss together with strawberries.
3. Cut a shortbread biscuit in half, lengthwise through the middle. Spoon the compote over it and place the top of the biscuit over it. Spoon more compote over the top.
4. Top with whipped cream