You’ll receive this request on the 21st of Spring, from Mayor Lewis. Apparently the mayor needs Truffle Oil. He also doesn’t want you to ask why. Oooookay. (Might be sexy? Might be sexy.)

To make Truffle Oil you’ll need an Oil Maker. Crafting an Oil Maker requires four things:
  • Level eight in Farming
  • Fifty Slimes
  • Twenty Hardwoods
  • One Gold Bar
Pretty standard stuff, all told, though the Slimes might take you a while to collect if you don’t have a Slime Hutch and / or much progress into the Mines or Skull Cavern.

That’s the first step. Your second goal is to get Truffles, which are rooted up by Pigs. To get a Pig you’ll need to upgrade a Barn to a Deluxe Barn, which requires 25,000 gold, 550 Wood, and 300 Stone. Pigs cost 16,000 gold from Marnie’s Ranch. Once the Pig has grown it will randomly find Truffles on your property, so all you need to do is follow it around for a while.

Drop the Truffle into the Oil Maker and you’ll have Truffle Oil a short time later. Take this to Lewis. He’ll give you a 750 gold reward, and you’ll earn some affection points with the old stud as well.