“A Taste of Everything” is a side quest in Wuthering Waves that you will do alongside Chixia. It doesn’t take long to complete, taking around 10 minutes or so. This will introduce you to basic mechanics such as Crafting, Synthesizing, and Cooking. It will also reward you with the following:

250 Union EXP

20 Astrite

3 Medium Resonance Potion

3 Medium Energy Core

12000 Shell Credits
How to Begin A Taste of Everything Side Quest
To start the A Taste of Everything side quest, you must find Uncle Mahe at his grocery shop. He will help you identify the recipe that Auntie Panhua gave you. This will then begin the side quest, prompting you to go to Koko next.
Find Koko
Koko can be found at the Shifang Pharmacy near the center of Jinzhou, approach her and talk to her to inquire more about the recipe.
Ask Uncle Wei and craft a weapon
After speaking with Koko, you must head to where Uncle Wei is (marked on the map). After the conversation, you will be prompted to create a weapon. You only need to craft one of the Guardian weapons, which only needs 10 Scarletthorns, to talk to Uncle Wei again.
Use the Synthesizer
After crafting a weapon and talking to Uncle Wei, you will head to the Synthesizer near one of the Resonance Beacons and found at the side of the Huaxu Academy. You must synthesize one ‘Basic Revival Inhaler’ to continue the quest.
Go to Auntie Panhua and cook
You will then go to Auntie Panhua and talk to her. You would then ‘explain the recipe’ to her, and after a few dialogues, you would then interact with the cooking station ‘Make the soup.’
Talk to Chixia
Chixia will be nearby after successfully making the soup and talking to Auntie Panhua. This will mark the end of the A Taste of Everything side quest!