Make about 2 to 3 slits upon each side of the tilapia deep enough to attain the bones.
Rub about 1 teaspoon of salt per side. Let the fish absorb the flavor for about 15 minutes.
Combine the tomato, onion, ginger, lemon juice, salt, and ground black pepper in a medium bowl. Mix well.
Scoop the tomato and onion mixture and stuff inside the cavity of the tilapia. Try to stuff all the mixture, if possible. Note that the tilapia should have a cut under the body due to the removal of the innards.
Wrap the tilapia in an aluminum foil. Make determined that all is covered.
Preheat oven to 370 degrees Fahrenheit.
Bake the tilapia for 20 minutes.
Remove the tilapia from the oven and then open the summit so that the fish is exposed. Brush the cooking oil over the fish.
Change the settings of the oven to broil (about 510 degrees Fahrenheit). Put the fish back in with the exposed summit. Broil for 15 minutes.
Remove the fish from the oven and serve with toyomansi.