In a large mixing bowl, whisk together lemon juice, corn starch, ground cumin, and ½ tsp each of turmeric, garam masala, and salt. This will create the seasoning base that will cling to the cauliflower and infuse it with flavor.

Heat 1 Tbsp of olive oil in a large skillet over medium-high heat. Add the cauliflower florets and cook, tossing occasionally, until browned and beginning to soften (7–8 minutes). Reduce heat to medium, transfer to the lemon-cornstarch mixture, and toss well to coat.

Return the seasoned cauliflower to the skillet and cook another 7–8 minutes, allowing it to char in spots and become crisp-tender. Set aside.

In the same skillet, add the remaining oil and the butter. Sauté the chopped onion until translucent (about 8 minutes). Stir in garlic, ginger, and tomato paste. Cook for 2 minutes until the mixture is fragrant and slightly caramelized.

Now add the remaining ½ tsp turmeric, 2½ tsp garam masala, and 1 tsp salt, along with paprika, cinnamon, and cayenne (if using). Let the spices toast for a minute before stirring in the tomato sauce and vegetable broth. Bring the mixture to a boil.

Reduce the heat to a gentle simmer. Stir in the heavy cream (or coconut milk for a dairy-free version). Add the roasted cauliflower back into the skillet. Simmer uncovered for about 15 minutes, allowing the sauce to thicken and cling to each floret.