In a large mixing bowl, combine the whisked yogurt, ginger-garlic paste, red chili powder, turmeric powder, garam masala, ground coriander, lemon juice, and salt. Mix well to form the marinade.
Add the paneer cubes to the marinade and gently coat them evenly. Cover and refrigerate for at least 20 minutes.
Heat a grill pan or non-stick skillet over medium heat and brush with 1 tablespoon vegetable oil.
Place the marinated paneer cubes on the pan and cook for 2-3 minutes on each side until lightly charred. Remove and set aside.
In a large pan, heat 2 tablespoons butter over medium heat. Add cumin seeds and let them sizzle for 30 seconds.
Add the finely chopped onions and sauté until golden brown, about 7-8 minutes.
Pour in the pureed tomatoes and cook for 8-10 minutes, stirring occasionally, until the oil starts to separate from the masala.
Add kasuri methi and salt. Stir well.
Add 1/2 cup water and bring the gravy to a gentle simmer.
Add the grilled paneer cubes to the gravy and mix gently to coat them.
Pour in the heavy cream and stir to combine. Cook for another 5 minutes on low heat, allowing the flavors to meld.
Garnish with chopped fresh cilantro leaves before serving.