Stardew Valley created by ConcernedApe.
Images used for educational purposes only.

You’ll trigger this quest during the second year on the farm. Wait until Spring 21st and you’ll get a letter from Pierre, asking you to get him some Sashimi. This quest therefore has two requirements:
  • The Sashimi recipe
  • The kitchen upgrade for your house, which costs 10,000 gold and 450 Wood
The second requirement is self-explanatory, and you can get it from the Carpenter’s Shop. The Sashimi recipe is a bit trickier. The recipe comes from Linus, who lives in a Tent to the north of Pelican Town and usually hangs out in that general area. You’ll be given Sashimi by Linus once you get him to at least two or three hearts’ worth of affection. Not too bad, but it does require several weeks of prep, as you can only give two gifts per day. Linus likes the following items:
  • Virtually every food item, including most foraged items (except those found in the Mines) - he particularly likes Coconuts and Cactus Fruits, both found in the Desert
  • Precious gems
  • Flowers
Once you’ve reached enough affection Linus will send the recipe to you in the mail. Now all you need is a fish. Any kind will do, from any source of water (besides the pond on your property, I suppose, which yields up garbage). Head into your kitchen, cook up Sashimi, and cart it over to Pierre’s General Store. He’ll give you 1,000 gold for your troubles via the Journal. Dayum.