In a pan, heat oil and add cumin and fennel seeds. Once the seeds begin to splutter, add the onions.
When the onions turn golden, add ginger, garlic, and serrano/green chili, stir, then add the tomatoes and cook for 10 minutes, or until the tomatoes become soft.
Add the spices, stir, then add the cauliflower florets and water and mix well.
Cover the pot with a lid and cook on medium heat for about 10-12 minutes, or until the cauliflower reaches your desired level of tenderness.
Garnish with cilantro and enjoy!