These recipes produce more of an item than they use, so feeding part of the output back in grows your supply.
Alaindustrial · Mutation duplicate · From Ala Industrial
Its other inputs are renewable, so this loop gives an unlimited supply of Nether Wart.
Create_cultivation · Cultivating · From Create: Cultivation Craft
Its other inputs are renewable, so this loop gives an unlimited supply of Nether Wart.
Mechanical_botany · Insolating · From Create: Mechanical Botany
+ minecraft:lava
Its other inputs are renewable, so this loop gives an unlimited supply of Nether Wart.
Minecraftcontentexpansion · Greenhouse · From MinecraftContentExpansion
Its other inputs are renewable, so this loop gives an unlimited supply of Nether Wart.
Vanillaautomated · Farmer recipe · From Vanilla Automated
Its other inputs are renewable, so this loop gives an unlimited supply of Nether Wart.
Alaindustrial · Mutation duplicate · From Ala Industrial
Its other inputs are renewable, so this loop gives an unlimited supply of Iron Ingot.