In a bowl, mix the flaked tuna with grated coconut, finely chopped onions, garlic, ginger, green chilies, turmeric powder, cumin powder, coriander powder, chili powder, salt, and black pepper. Combine well.
Heat vegetable oil in a pan over medium heat.
Add the onion mixture and cook until the onions are soft and translucent.
Add the tuna-coconut mixture to the pan. Stir and cook for about 5 minutes to allow the flavors to blend.
Transfer the mixture to a baking dish, pressing it down evenly.
Pour the beaten egg over the mixture to bind it together.
Preheat your oven to 375°F (190°C).
Bake the Boakibaa for about 25-30 minutes, or until the top is golden brown and set.
Allow the Kulhi Boakibaa to cool slightly before cutting into squares.
Garnish with fresh coriander and serve with lemon wedges if desired.
Enjoy your meal!