For the marinade: In a bowl, mix the minced garlic, cumin, fish seasoning, paprika, salt, and lemon juice until combined. Rub the marinade all over the fish, inside and out.
Cover the fish and let it marinate for about 1 hour to absorb the flavors.
For the grilling mixture: Place the onion, tomatoes, parsley, fresh coriander, bell pepper, carrots, garlic, and tomato paste in a food processor. Process the ingredients until they form a smooth mixture. Season with salt, black pepper, cumin, ground coriander, fish seasoning, lemon juice, and olive oil. Stir the mixture well until fully combined.
Line a baking tray with aluminum foil. Place the marinated grouper on the tray, then spread the grilling mixture evenly over the top until the fish is completely covered.
Bake the fish in the oven for about 40 minutes, or until it is fully cooked.
Remove the grouper from the oven, place it on a serving platter, and serve hot.