Prue Leith's Cheese & Chive Scones with Homemade Butter recipe

Ingredients

• 400ml double cream
• ¼ tsp fine salt
• 225g self-raising flour, plus extra for dusting
• ½ tsp salt
• ½ tsp baking powder
• 1 tsp English mustard powder
• 30g homemade butter (above), cut into small pieces
• 50g parmesan, finely grated
• 2 tbsp finely chopped chives
• 150ml buttermilk (from making the butter)
• 1 egg, beaten, to glaze