In a large mixing bowl, add all the tandoori marinade ingredients including greek yogurt, ginger & garlic paste, lemon juice, all the listed ground spices, mustard oil, kasuri methi and salt.
Using a sturdy whisk, mix everything together until the marinade is smooth, and well combined. See how the color of the marinade turns out. Sometimes it’s vibrant enough on its own, especially if you’re after a deep, smoky red rather than a bright orange. If desired, add a few drops of red food color(gives it restaurant look!).
Pat the thawed shrimp dry using paper towels to remove any excess moisture. This helps the marinade cling better and ensures the shrimp sear properly. Add the shrimp to the marinade.
Using a spatula or, even better, your hands, gently toss and massage the marinade into the shrimp so they’re thoroughly coated. Cover the bowl and let it sit on the kitchen counter for 20–30 minutes. This gives the shrimp time to absorb the flavor without getting rubbery (which can happen if they’re marinated too long).
Place a cast iron pan on the stove and heat it over high flame. Let it get really smoking hot. This is key to getting that signature tandoori char and sear. Once the pan is ready, lightly brush the surface with ghee (or oil). Carefully place the marinated shrimp in a single layer, spacing them out so they aren’t crowded (work in batches if necessary).
Let the shrimp cook undisturbed for 1 to 3 minutes. You’re looking for a deep golden crust to form on the bottom. Once that’s achieved, flip them over and sear the other side for another 1 to 3 minutes, or until they’re cooked through. Once cooked, will have opaque in the center, with a lightly charred exterior and curled tails.
Transfer the hot, sizzling shrimp straight to a platter and serve right away while they’re juicy and tender.