Devein, clean, and drain shrimp.
Boil pasta according to package directions using 1 tbsp salt in the water. Drain and set aside, reserving 1 cup pasta water. About 1/2 to 3/4 of a box of pasta is needed in this recipe.
In a skillet, heat oil and sauté onions until golden.
Add ginger paste and garlic paste, followed by all the spices (salt, coriander, cumin, Kashmiri red chili powder, garam masala & turmeric). Sauté for about 5 minutes until the oil separates, adding a splash of water to prevent sticking/burning.
Add Greek yogurt, tandoori paste, tomato paste & sugar. Sauté for another 3-4 minutes.
Add shrimp and stir it around until they are no longer gray (do not overcook).
Add heavy cream and let the sauce come to a simmer.
Stir in boiled pasta and let it simmer for another 5 minutes or so. Add the reserved pasta water to slightly thin out the sauce. Adjust salt.
Garnish with chopped cilantro.
Sprinkle grated parmesan and crushed red pepper flakes on top (optional).