Step 1

Preheat the oven to 220C/200C Fan/Gas Line a baking sheet with baking paper.

Step 2

Whisk the milk and lemon juice together and set aside for 5 minutes to thicken.

Step 3

Sift the flour, baking powder, xanthan gum and salt into a large mixing bowl.

Step 4

Add the butter and lightly rub in until there are only small flecks of butter visible.

Step 5

Stir in the sugar and the sultanas, if using.

Step 6

Make a well in the middle of the mixture, add the thickened milk and use a palette knife to cut the wet ingredients into the dry, then gently mix with your hands until just combined.

Step 7

Turn the dough out onto a lightly floured work surface and very gently press it out to about 3cm/1¼in thick.

Step 8

Use a 6cm/2½in plain round cutter to stamp out rounds of dough and place on the baking sheet. Gather the off-cuts into a ball, gently roll and stamp out more scones.

Step 9

Brush the tops with milk, sprinkle with sugar and bake for about 12 minutes or until well risen and golden brown.

Step 10

Leave to cool on a wire rack.

Step 11

Split in half and serve with jam and clotted cream.