Barbecued Chicken Pizza

Ingredients

• 400g crushed tomatoes (1 tin)
• 2 garlic cloves, crushed
• 1 handful basil, chopped
• salt
• pepper
• 2¼ cups spelt flour
• 1 tablespoon baking powder
• ½ tablespoon salt
• 1 cup Greek yoghurt
• 1 tablespoon olive oil
• extra spelt flour for kneading
• 400g cooked chicken, chopped
• ½ red onion, sliced
• 8 mushrooms, sliced
• 4 slices prosciutto, torn
• 100g feta, crumbled
• smoky barbecue sauce
• 1 handful rocket leaves