I don’t think there’s a recipe or particular food that will make significant difference unless it has a lot of zinc (which definitely works). Instead of experimenting with food, research what substances increase load size and then look for foods that contain it or simply take a supplement. I think it’s easier to drink a tablet of zinc a day than to eat oyster, but that’s just me.
Of course, genetics are important, but if you do something to increase the amount of semen and strengthen the muscle that launches it, there has to be difference. :)