1 Put the flour into a mixing bowl with the salt and the oil and mix well. Add the lukewarm water and knead to a pliable dough. Cover and leave to rest at room temperature for about 30 minutes.
2 Heat the oven to 180°C (160° fan) 350°F gas 4. Grease a baking tray.
3 Put the spinach into a pan with a little salted water and cook over a high heat, stirring occasionally, until it wilts. Drain, rinse in cold water and drain thoroughly. Squeeze out the spinach and chop finely.
4 Mix together the spring onions. ricotta, spinach, lemon zest and egg and season to taste with salt, pepper and nutmeg.
5 Knead the dough on a lightly floured surface. Roll out thinly and cut into 10 cm|4" squares.
6 Put a little filling on each square and fold in half diagonally. Press the edges together with a fork.
7 Put the pasties on the baking tray. Beat the egg yolk with the milk and brush over the pasties. Bake for about 25 minutes, until lightly browned.