Welsh rarebit muffins

INGREDIENTS

• 225g self-raising flour
• 50g plain flour
• 1 tsp baking powder
• ½ level tsp bicarbonate of soda
• ¼ tsp salt
• ½ level tsp mustard powder
• 100g strong cheese , half grated, half cubed
• 6 tbsp vegetable oil
• 150g Greek yogurt
• 125ml milk
• 1 egg
• 1 tbsp Worcestershire sauce