In a large bowl, combine the shrimp with the green seasoning, garlic, curry powder, tomatoes, scallions, onion, celery, chadon beni, and thyme. Mix well to coat the shrimp.

Cover and let marinate for at least 20 minutes.

Heat the oil in a large pot over medium-high heat. Add the onion, scallion, celery, and garlic. Sauté until the aromatics begin to darken.

Reduce the heat to medium-low. Add the curry powder, geera, garam masala, and turmeric. Cook, stirring frequently, until the curry mixture darkens and becomes grainy.

Add the marinated shrimp along with all the seasonings from the bowl. Stir well to coat the shrimp in the curry mixture.

Cook for about 4 minutes, allowing the shrimp to release its liquid. Add the pimento peppers or pimento sauce and a little water as needed to create the amount of gravy you prefer. If using a whole hot pepper, add it now without breaking it.

Season with salt, black pepper, and pepper sauce to taste, if using. Simmer for about 3 minutes more, or just until the shrimp are cooked through.

Remove from the heat and serve hot with rice or roti.