In a large mixing bowl, combine fresh lemon juice, corn starch, ground cumin, ½ teaspoon of turmeric, 2 ½ teaspoons of garam masala, and ½ teaspoon of salt. Toss in the cauliflower florets until they are well-coated with the mixture.

Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the coated cauliflower and sauté for 7-8 minutes. Transfer the browned cauliflower to a bowl.

In the same skillet, add the remaining tablespoon of oil and 2 tablespoons of unsalted butter. Add the chopped yellow onion and cook for about 8 minutes until translucent. Then add minced garlic, freshly grated ginger, and tomato paste; cook for 2 minutes.

Stir in the remaining ½ teaspoon of turmeric, 2 ½ teaspoons of garam masala, paprika, a pinch of ground cinnamon, and cayenne pepper. Add the canned tomato sauce and vegetable broth, bringing the mixture to a boil.

Reduce heat to low and stir in heavy cream. Return the sautéed cauliflower, stir gently, and let simmer uncovered for 15 minutes.

Garnish with freshly chopped cilantro, serve hot over basmati rice, and add a dollop of Greek yogurt.