Add 2 tablespoons ghee, onion, ginger, garlic, Serrano pepper, and spices to your crock pot. Set on high for 1 hour.While that’s cooking, grab a very large pot. Add the mustard and spinach leaves to the large pot - then fill with water (do not put lid on pot!*).Bring the pot to a boil and cook for 5 minutes. Drain leaves and let them cool.Once cool, place leaves in a blender and blend to your desired consistency (add a little water as needed to help you blend).Place the blended leaves into your crock pot, reduce heat to low, put lid on and cook for 2 hours.After 2 hours, add 1 tablespoon ghee, garam masala and pinch of kasoori/fenugreek leaves. Mix well and let this cook for another hour on low.Serve this saag with a heaping spoonful of ghee on top!