In a large pot, bring water to a boil and add the shark meat.
Boil for about 10 minutes, then drain and let cool.
Once cooled, shred the shark meat into small pieces, discarding any bones.
In a large skillet, heat the vegetable oil over medium heat.
Add the chopped onion and sauté until translucent, about 5 minutes.
Add the minced garlic and grated ginger, and cook for another minute until fragrant.
Stir in the chopped tomatoes and cook until they begin to soften, about 5 minutes.
Add the ground turmeric, ground cumin, ground coriander, black pepper, and salt. Cook for another 2 minutes, stirring frequently.
Add the shredded shark meat to the skillet and stir to combine with the tomato and spice mixture.
Pour in the lemon juice and add the finely chopped chili pepper (if using).
Reduce the heat to low and let the mixture simmer for about 10-15 minutes, or until the flavors are well melded. Stir occasionally.
Remove from heat and garnish with fresh chopped cilantro or parsley.
Enjoy your meal!