Here is what you will need
one large yellow onion, roughly chopped
1 teaspoon cumin seeds
1 teaspoon black mustard seeds
1 teaspoon salt
1/2 teaspoon turmeric (these are generous half teaspoons)
1/2 teaspoon cumin powder (again, generous)
1/2 teaspoon red pepper powder
Saute in the pressure-cooker until the onions start to become translucent.
Add three heaping cups of fresh spinach (which is what I had today, but you can use a geneous cup of frozen spinach, too)
Saute until the spinach cooks down quite a bit:
Add 1 tablespoon of coriander powder, 2 small roughly sliced tomatoes, and one heaping cup of yellow split dal and saute the whole mixture for about a minute or so:
Cover this with three cups of water, seal the pressure-cooker and cook on high for 18 minutes.