Adapted from Laurel's Kitchen. Serve this with basmati rice and steamed vegetables and you have yourself a filling, nutritious meal. Unfortunately, for this particular recipe there isn't any room for substitution or omission of ingredients.
In large pan boil the split peas in plenty of water for about 30 minutes until tender. If the water starts evaporating too quickly, add more as needed. By the end of the cooking time, the split peas should have the dry consistency of mashed potatoes, the majority of the lentils will have lost their shape and most of the water will have evaporated.
Remove pot from range, drain the water from the lentils and stir in salt. Cover and set aside.
Chop onion, and combine with the jalapeno, turmeric and curry powder.
Heat the oil or ghee over medium heat in a heavy saute pan with lid. When oil is hot, carefully add the black mustard seeds. Stand back as they may pop up into your face. Cover the pan with the lid and continue cooking the mustard seeds until the popping quiets down.
Now add the onion mixture to the pan and saute until the onion is translucent and golden. Finally, stir in the cooked split peas. Remove from heat and stir in the lemon juice. Taste and adjust seasoning if necessary.