Put the flour, the baking powder, 250 g of yogurt and the salt into a large bowl.
Mix the ingredients until they come together into a ball.
Divide the dough into 4 balls and using a little flour flatten them, then cook one by one in a slightly oiled pan on medium heat until golden brown on both sides.
Meanwhile thinly slice the potatoes and stir-fry them in a pan with a little oil, then add salt and pepper.
When the Naan bread is ready, fill them with the remaining yogurt, some slices of Prosciutto di San Daniele and watercress leaves.
Season with oil, salt and chili pepper. Serve with the warm fingerling potatoes and frisee salad.
