craftingTable.removeRecipe(<item:create:chute>);
craftingTable.addShaped("chute", <item:create:chute>, [
    [<item:create:andesite_alloy>, <item:create:andesite_alloy>, <item:minecraft:air>],
    [<item:create:iron_sheet>, <item:create:iron_sheet>, <item:minecraft:air>],
    [<item:minecraft:air>, <item:minecraft:air>, <item:minecraft:air>]
]);
