Wash cauliflower floret in a large vessel and drain water in a colander. Set aside.
In a pan, fry garlic on a medium-low flame for 10 sec. Then add whole spices (cumin, fenugreek seeds, mustard seeds). Let them pop.
Then mix in chopped onions and salt. Fry till onions are soft, around 5 minutes.
Now add remaining spices, coriander, and turmeric, green chilli and ginger paste. Fry well so the flavors are released.
Add tomatoes, dry fenugreek leaves, and sugar. Cover and simmer for 5 minutes on medium-low flame till tomato softens and the colour darkens.
Next, add potatoes and pea, cover and cook for 10 minutes. Add about ½ cup water if gravy is dry to avoid burning, Cook on medium low heat.
When the potatoes are half cooked, stir in cauliflower floret. Cook for another 7-10 minutes until cauliflower florets are soft. Add butter and fry on high for 2 minutes until oil release.
Garnish with green chillies, coriander and allspice powder.