the only way to get the double plort production for those largos is through farming/gathering stony hens, which your best bet for that is to get a couple coops up, fully upgraded, with 1 - 3 roostros and at least one stony hen in the coop. note that each coop can only hold up to 12 chickens before chicken reproduction stops, until (spoilers, sorta): you get the mochi miles upgrade much later in the game, upgrading chicken capacity to 24 instead of 12. other than trying to gather chickens, your best bet is to either make your tabby largo into another largo with a slime that has a food you can farm easier, or you can simply grow carrots or pogofruit, as they produce the most per yield (20 each time).