put some grocery shrimps, scallops, carrot, galic (just a little), nori, and whatever you want it to eat in a blender and then add a little water, pour the mix in a ziplock bag, spread it thin enough so that you can break it into little pieces, put it in the frige. Feed your lion whenever you see its stomach really needs something to stuff in
It might doesn't like the food at first, so let him be hungry for a few days, then feed him Good luck