Heat the oil in a kadai and fry the urad dal. As the urad dal turns slight brown, add the onions and chillies and fry for some time. After the onion is fried, add the cut spinach (frozen/fresh), cover with a lid for 3 minutes, remove the lid and stir fry for another 2 minutes till all the water evaporates. Add salt to taste and it will be done. This is very easy to make and takes very little time to prepare.