Sieve the first 4 ingredients onto a kneading platter. Make a well in the centre; mix in 1 cup water and milk mixture and knead to make a dough. Cover with a moist cloth and keep aside for 10 minutes.

Add oil and knead again. Cover the dough and keep aside for 2 hours till it rises. Divide the dough into 6 balls. Flatten balls and sprinkle onion and melon seeds. Cover and keep aside for 5 minutes.

Roll and flatten each ball between your palms. Stretch the dough to one side to give an elongated shape (naan). Using oven gloves, stick the naan inside a hot tandoor for 3 minutes or place the naan on a greased tray and bake in an oven for 10 minutes at 180°C (350°F). Apply butter (optional) and serve.