Preheat the oven to 200C/400F and line two baking trays with baking parchment or a silicone mat. Place the flour, salt and butter in a large bowl and rub together with your fingertips until most of the butter lumps have gone. Add the sugar and raisins and give it a quick mix.
In a separate bowl, mix the sourdough starter, milk and vanilla extract. Pour ¾ of the starter mixture into the flour mixture and use a round ended knife to work the mixture together. Add more of the starter mixture and work in gently until you have a soft, slightly sticky dough. Don't overwork, or you'll get tough scones.
Tip out the dough onto a floured surface and flatten it out with your hands so that it's about 3cm (1 ⅛ inches) thick.
Use a round cutter dipped in flour (to prevent it sticking) and cut out your scones. Using a 7cm (2 ¾ inch) diameter cutter should give you 10 scones or an 8cm (3 ⅛ inch) diameter cutter for 8 scones. Make sure you just press the cutter down rather than twist it - otherwise you'll get scones that rise a bit wonky. Gather the leftover dough, gently rework and cut out the rest of the scones until all the dough is used.
Place on the prepared baking tray, brush with the egg wash place in the oven for 13-15 minutes until golden brown.
Remove from the oven, leave to cool.
For the compote, place half the strawberries 1 cup (150g), all the rhubarb, sugar and water into a medium-sized sauce pan.
Place the lid on and heat over a medium heat 25-30 minutes, stirring occasionally, until the rhubarb breaks down.
Add in the remaining strawberries and cook for a further 5 minutes until just softened.
Turn off the heat and leave to cool.
To assemble the scones, slice in half and spread each scone with a tablespoon of clotted cream. Drizzle on a tablespoon of the rhubarb and strawberry compote and add a couple of slices of strawberry. Place the top of the scone on top and repeat with the remaining scones.
Serve with any remaining rhubarb and strawberry compote.
How to make a sourdough starter:
**note** this is a minimum 7-day process: I used a slightly modified version of the sourdough starter from King Arthur flour.To start you'll need:
1 cup (120g) wholewheat flour
½ cup (120ml) lukewarm water
Each time you feed your starter you'll need:
1 cup (120g) plain (all purpose) flour
½ cup (120ml) cool water
Instructions:Day 1: Mix the flour and water in a large non-reactive (I used a large glass mason jar) container. It needs to be at least 1-quart (approx 1 litre) in capacity to allow for growth. Stir everything together until thoroughly combined. Loosely cover the jar and let it sit in a warm room for 24 hours.Day 2: Discard half of the starter from the jar, and feed with 1 cup (120g) plain (all purpose) flour and ½ cup (120ml) cool water. Stir thoroughly, loosely cover and let it sit in a warm room for 24 hours.Day 3: It should be a little bubbly by now. Repeat the steps from day 2 - discarding half the starter, feeding, mixing and covering, but for the third day, you need to disacrd and feed twice (approx 12 ish hours apart).Day 4: Repeat the twice daily discarding, feeding mixing, and covering.Day 5 - 7: Repeat the twice daily discarding, feeding mixing, and covering until you have a vigorous (risen, bubbly) starter. You may get this as early as day 5, or it may take a couple of days longer.***Once you reach this stage, you can use the sourdough discard to make the scones and store the remaining sourdough starter in the fridge, discarding and feeding once a week (use to make amazing sourdough bread).
How to make a non-sourdough version:
To make a non-sourdough version, add an extra 4 tbsp flour to the dry mix. Then replace the wet mixture (the starter, milk and vanilla) with 1 large egg, 1 cup plus 3 tbsp (285ml) buttermilk and 1 tsp vanilla extract. Follow the rest of the sourdough scone instructions in the same way.
Nutritional Information is per scone, filled with cream and compote.