Combine the cayenne, coriander, black pepper, nutmeg, turmeric, and garam masala in a small bowl, add the 3 tbsp. (1. 5 oz / 45g) of water, and mix well to create a smooth spice paste.
Melt the ghee or unsalted butter in a 5-quart (4. 7-liter) nonstick pan over moderate heat, add the asafetida to sizzle for a few seconds, then pour in the spice mixture and fry for about 2 minutes to release the oils.
Pack the fresh spinach into the pan, sprinkle evenly with the salt, cover the pan with a lid, and reduce the heat to let it steam for 6 to 8 minutes.
Turn the spinach leaves over using tongs or a spatula so that the uncooked top layer mixes with the cooked bottom layer, replace the lid, and cook for an additional 2 to 3 minutes until fully tender.
Remove the pan from the heat, gently stir in your 0. 5 cups (4 oz / 113g) of chosen dairy until combined, return to the heat to rewarm briefly without boiling (to prevent curdling), and serve immediately.