In a small bowl, mix the lemon juice, olive oil, cumin, coriander, paprika, turmeric, black pepper, and salt.
Rub the marinade all over the fish fillets. Let the fish marinate for at least 30 minutes in the refrigerator.
Heat a little oil in a large skillet or pan over medium heat.
Add the chopped onions and cook until translucent.
Stir in the minced garlic and cook for another minute.
Add the chopped tomato and green bell pepper. Cook for about 5 minutes until the vegetables are softened.
Stir in the tomato paste and water. Simmer for 5 minutes, allowing the sauce to thicken slightly.
Heat a little more oil in another skillet or pan over medium heat.
Add the marinated fish fillets and cook for about 4-5 minutes on each side, or until the fish is cooked through and flaky.
Place the cooked fish fillets on a serving dish.
Pour the prepared sauce over the fish.
Garnish with fresh cilantro or parsley.
Enjoy your meal!