In a medium saucepan, combine the dal, salt, and 1 ½ cups water. Bring to a boil, then reduce the heat to maintain a simmer. Cook for 20 minutes, or until the dal is soft.
In a separate large pot or Dutch oven, combine the oil, coriander, cumin, mustard, hingwastak, pepper, nutmeg, and curry leaves. Cook over low heat for about 3 minutes until the spices are fragrant and browning. Add the garlic, shallot, ginger, and celery, stir to coat in the spices, and cook for another 3 minutes.
Add the broccoli, Brussels sprouts, dandelion, and spinach. Stir to coat in the spices, and cook for about 5 minutes to begin softening the vegetables. Add the water, lightly cover the pot with a lid, and cook over medium-low heat for about 30 minutes, until the vegetables are very soft—softer than you think they need to be.
Remove from heat and puree the mixture with an immersion blender until smooth. Stir in the lemon juice, and taste to adjust for spices.
Serve the saag alongside a scoop of dal and finish with a healthy pinch of cilantro, salt, and/or additional oil or ghee, as desired.
You will likely have more vegetables left over than dal; store the saag in an airtight container for up to 3 days, and prepare fresh dal for additional servings.
