These recipes produce more of an item than they use, so feeding part of the output back in grows your supply.
Create_cultivation · Cultivating · From Create: Cultivation Craft
Its other inputs are renewable, so this loop gives an unlimited supply of Wither Rose.
Farmingutils · Internal farmer · From FarmingUtils
Its other inputs are renewable, so this loop gives an unlimited supply of Wither Rose.
Cyclic · Solidifier · From Cyclic
Its other inputs are renewable, so this loop gives an unlimited supply of Ender Pearl.
Alaindustrial · Mutation duplicate · From Ala Industrial
Its other inputs are renewable, so this loop gives an unlimited supply of Glowstone Dust.