Clean the fish well of their heads, tails and spines, salt them, soak them with fresh lemon juice and let them marinade for 5-10 minutes.
Coat them with oil and put them to bake on the grill, turning them over several times and smearing them with oil.
Chop the parsley finely and mix it with the melted butter. Allow the butter to solidify in the freezer, then cut it into slices. In the stomachs of the baked bonitos, put a few slices of the parsley-flavored butter.