Cook moong dal with half the turmeric powder and asafoetida till soft. Heat oil (or ghee) in a pan.
Add cumin seeds, garlic, ginger, green chillies and sauté for one minute. Add onion and continue to sauté till onion gets lightly browned.
Add spinach and sauté for half a minute. Add the remaining turmeric powder and stir. Add dal and mix well.
Add one cup water and salt and stir. Add lemon juice just before serving.