Step 1Heat oil over medium-high heat in large skillet. Add onion and cook, stirring occasionally, until lightly browned, about 6 to 8 minutes. Add garlic, ginger and chiles and cook 2 minutes more. Add coriander, cumin, cinnamon, turmeric, mustard seeds and salt. Cook, stirring until very fragrant, about 3 minutes. Add cauliflower and mix well. Add coconut milk and lemon juice, reduce heat and simmer 5 minutes.