Of Swords and Dumplings is a Side Quest in The Witcher 3 that takes place in Novigrad. This quest can be picked up fairly early in the game and has a suggested level of 24, but can be done at lower levels. Completing this quest will unlock Hattori as a master swordsmith/blacksmith.

Of Swords and Dumplings Walkthrough

After talking to Hattori to pick up the quest, head to the docks, and wait until after dusk to talk to Hattori. If you do not find him after dusk, keep waiting/meditating in the area until he eventually shows. Once he shows, talk to him, then follow him to meet the supplier.

You'll meet the supplier, where you can help Hattori to negotiate terms for the supplies. The initial offer is 50%, you can accept it, or keep haggling. If you keep haggling you should be able to get the deal down to at least 35%. (When the timer starts, hold your ground and respond with "Fine, no deal". The bandits will give in and accept 25%.) After the deal concludes, some of Cleaver's men appear, you will need to kill them to carry on.

After dealing with Cleaver's men, leave the area. Hattori runs away scared. Head to Hattori's shop and talk to him. He wants Geralt to help find him a body guard.

Head to the Sturgeon and find Sukrus, who Hattori wants to become his bodyguard. Once arriving, Sukrus challenges Geralt to a fist fight. After beating him, head inside with Sukrus and have a drink. Sukrus wants help with getting money from his brother in law before offering to help Geralt.

Head towards the Skellige merchant, and convince him to pay Sukrus, or destroy his goods. Once that issue habeen s resolved, head back toward Sukrus and let him know you have succeeded.

With Sukrus now recruited, head back to Hattori. Hattori now mentions he is missing some crafting supplies. Your next mission for Hattori is to get Sukrus and then to borrow/steal some crafting supplies. Sukrus has a plan, so the next step is to meet him by the Sturgeon.

Head to the warehouse, and talk to guard. Convince him to let you into the warehouse. Once inside, use your witcher senses to mark the crates with the supplies for Sukrus to take. Once this is done, head outside, and a fight will ensue with Erst van Hoorn and his thugs.

After dealing with them, head back to Hattori to collect your reward. You will need to wait a full day to receive the quest reward sword from him.