This is probably the easiest hunt haha. The hardest part is naming the episodes.
That being said, the first thing that came to mind: The Uncanny Counter 2: Counter Punch, episode 1

On Because it's My First Life, Se-Hee goes in Ji-Ho's family to make kimchi. It was a nice episode with Ji-Ho protecting him from drinking, the kiss scene etc.

In one of the first episodes of HEALER, Chae Young-shin watches the news while making kimchi.

The one in Because This is My First Life is definitely the most memorable. My Roommate is a Gumiho also had the gumiho suffering through a kimchi-making session in Ep. 12.

Just one rang in my head immediately I saw this prompt: Because This Life is My First episode 11. A very good showcase of Lee Min-ki's muscle and flex of his physique.

Coffee Prince: Yoo Joo makes 깍두기 (radish kimchi) after she and Han Sung get married. When he tastes it, the expression on his face and his slowed down chewing clearly indicate it's bad. She says, "but the color is really pretty" and he says that is to be expected because his wife is an artist. Ugh, RIP Lee Sun Kyun.
Marriage, Not Dating: While we never really see the mother-in-law making kimchi, her kimchi is the key ingredient in making the fusion cheese kimchi jeon a hit at the FL's bar restaurant so the FL and the MIL have a long negotiation about it.
The Real Has Come (sigh, what could have been drama): The FL helps the grandmother make kimchi after moving into the annex as part of being bullied and/or being filial.

The one that comes top of mind is in This Is My First Life with Lee Min Ki in full outfit helping with the kimchi making

Toward the end of Doom at your service, they do a kid-pool of kimchi with the whole family.
In Lovelly runner FL cut green onions with her Almeoni.
in Tale of the Nine-Tailed 1938 the brothers are recruited to make kimchi maybe before the baby ?
In Alchemy of Souls Season 2: Light and Shadow, we have the kimchi making and the reluctant kimchi eating for Park Jin recipe is not one to keep.
Miss Oh tried to learn to make good kimchi, but her mother's is better (at least it is not the one made by Another Miss Oh.
There is communal kimchi making in the North Korean village, and Seri takes part. Crash landing on you.

I do not visualise the scenes in Doctor Slump, If you wish upon me, Fight for my way, Her private life,

I've watched so many kdramas that I have a lot of treasures to open but I'll go with "LEE MIN HO making kimchi in BOYS OVER FLOWERS"

Because This Is My First Life wiped out all my memories of other kimchi scenes, but I'm going to out on a limb with Kimchi Family, there must have been kimchi-making in there.

The kimchi slap in the tv show the grandfather is watching in Business Proposal is priceless.

My favorite was already mentioned, Because This is Our First Life
The ajummas in CLOY
In Healer FL helps her dad make kimchi and pretends one of the cabbage leaves is her boyfriend
Did the FL make the kimchi for her white kimchi ravioli? Over and over. I learned he word again dashi from that ep!

I have just watched it, so I'll mention it.
The FL makes radish kimchi for the ML in "I'm sorry, I love you". He asked her to make kimchi for him before she went abroad.
She said she knew how to make radish kimchi, so they went to the supermarket in order to buy all the ingredients and then both of them make a very spicy kimchi.

Episode 7.