Heat the oil in a skillet over medium heat. Add mustard seeds, curry leaves, and the dried red chili. Allow them to sizzle for 30 seconds.
Add the sliced onion, minced ginger, and minced garlic. Sauté until the onion softens and becomes translucent.
Stir in the turmeric powder, cumin powder, and fennel powder.
Add the sliced green chili and chopped cauliflower. Mix well to coat the cauliflower with the spices.
Cook for about 5 minutes, stirring occasionally until the cauliflower begins to soften.
Add the grated coconut and salt. Stir-fry for another 3 minutes until everything is well combined.
Taste and adjust seasoning if needed. Serve warm with rice, curry, or roti.