The Legend Of Zelda: Tears Of The Kingdom surpassed expectations, especially when it came to the length of the game. The countless hours that you are able to put into this game is thanks to all the great side quests as well as the main story.
One of these quests is The Broken Slate. This takes place after you went to the top of Polymous Mountain to meet Sidon and began the Sidon of the Zora quest. There are a few steps you must complete prior to finding and beginning this quest.
How To Start The Broken Slate
The steps you must take that lead up to this mission include going to Toto Lake to speak with Jiahto the historian. Toto Lake will be to the right of Upland Zorana. If you see Dunma standing on a platform, you should speak to them first, then go find Jiahto in the nearby cave. The Broken Slate will be activated once you speak with Jiahto, and it's actually a bonus part of the main quest line piggybacking from Sidon of the Zora.
How To Complete The Broken Slate
After you speak with Jiahto, head out of the cave. If you pan the camera to look at the front of Link, you will see a boulder to the right. You will want to climb this boulder and use a Splash Fruit on it. Then, equip Ultrahand to move the blue slate. You may have to disengage from it to jump down off the boulder, then reattach the Ultrahand to bring it into the cave.
Follow the control instructions to rotate the slate, so you can place it on the wall like a puzzle piece. Step a bit closer until you're able to snap the slate back in place. You will receive a notification that this quest is complete as Jiahto admires the fixed slate.