In a large bowl, combine the fresh lemon juice, corn starch, ground cumin, 1/2 teaspoon of turmeric, 2 1/2 teaspoons of garam masala, and 1/2 teaspoon of salt until smooth. Cut one medium head of cauliflower into uniform florets and toss them in this mixture.

Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the cauliflower florets and cook for 7 to 8 minutes until browned and softened.

Return the cauliflower to the bowl with the corn starch mixture and toss to coat again. Cook for an additional 7 to 8 minutes until charred and crisp-tender.

In the same skillet, add the remaining tablespoon of olive oil and 3 tablespoons of unsalted butter. Sauté one finely chopped yellow onion for about 8 minutes until translucent.

Stir in 3 minced garlic cloves, 2 teaspoons of freshly grated ginger, and 2 tablespoons of tomato paste, cooking for 2 minutes until aromatic.

Sprinkle in the remaining 1/2 teaspoon of turmeric, 2 1/2 teaspoons of garam masala, 1 teaspoon of paprika, a pinch of ground cinnamon, and cayenne pepper if desired. Stir and sauté for an additional minute.

Pour in 8 ounces of tomato sauce and 2 cups of vegetable broth, stirring to combine. Bring to a boil, then reduce to a simmer.

Stir in 1/2 cup of heavy cream and gently add the crisp-tender cauliflower back into the skillet, coating it evenly with the rich sauce. Allow to simmer for about 15 minutes.

Garnish with fresh cilantro and serve hot over fluffy basmati rice or quinoa, with a dollop of Greek yogurt on top.