In a large bowl, mix lemon juice, corn starch, ground cumin, ground turmeric, garam masala, and salt until well combined. Toss cauliflower florets in this mixture until evenly coated.

Heat olive oil in a large skillet over medium-high heat. Add the coated cauliflower and cook for 7-8 minutes until browned and tender.

Reduce the heat to medium, add olive oil and unsalted butter. Once melted, add onion and sauté for 8 minutes until translucent.

Stir in garlic, ginger, and tomato paste; cook for 2 minutes until aromatic.

Add the remaining spices, tomato sauce, and vegetable broth. Bring to a boil, then simmer for 5 minutes.

Incorporate heavy cream into the sauce and stir well. Add sautéed cauliflower and mix until coated.

Simmer uncovered for 15 minutes, allowing the flavors to deepen.

Garnish Butter Cauliflower with chopped cilantro and serve warm over basmati rice with a dollop of Greek yogurt.