Start by finely chopping the onions, ginger, and garlic.
In a large skillet or wok, heat 2 tablespoons of neutral oil over medium heat. Add the chopped onions and sauté until they turn golden brown, about 5-7 minutes.
Stir in the minced ginger and garlic, cooking for an additional 1-2 minutes until they are fragrant.
Add ground coriander, fenugreek, garam masala, cumin, paprika, salt, turmeric, cardamom, and cayenne pepper. Stir well to coat the onions in the spices, allowing them to toast slightly for about 1 minute.
Add the tomato paste and 2 tablespoons of water to the skillet. Stir to combine, letting the mixture simmer for about 2-3 minutes.
Now, add the thawed chopped spinach to the skillet. Stir well to combine with the spice mixture, cooking for another 3-4 minutes until heated through.
Finally, add the raw peeled shrimp to the skillet. Stir gently to mix everything together. Cook for about 5-7 minutes, or until the shrimp are pink and opaque.
Taste your Shrimp Saag and adjust the seasoning if needed.