This could be a controversial statement, but I think kimchi is just another variation of sauerkraut. If you go back and read my post on sauerkraut, the basic technique is to cut cabbage, add salt, pack into a jar, and ferment at room temperature. We can add other greens, fruit, herbs, and spices to add variation as long as the technique and salt level remain intact. My kimchi method is the same as my sauerkraut method except that it has a few additional ingredients. Realizing this commonality was enlightening because it freed me from needing to follow recipes. Through experimentation and diligent note taking, I have dialed in a basic recipe that works for my palate, but I would encourage everyone to make kimchi the way you like it. Heck, you can even skip the red pepper if you are not a fan of spicy hot food since this was the traditional way kimchi was made until chile peppers were introduced to Korea around the 17th century.
One book I would highly recommend is The Kimchi Cookbook by Lauryn Chun. According to her, "there are more than 160 foundational recipes for kimchi, and every Korean family has its own version of the basic recipe based on their regional style." Not only does this book cover a wide variety of recipes categorized by season, there are also some very exciting ideas about cooking with your kimchi such as kimchi slaw, kimchi risotto, grilled kimchi cheese sandwich, red curry mussels with kimchi, and kimchi grapefruit Margarita. My favorite recipe from this book is the scalloped potatoes with kimchi where thinly sliced potatoes are layered with cream, cheese, and kimchi and baked. To call this flavor combination brilliant is no overstatement as I have made this fantastic dish many times.
There is no particular reason for the weights of cabbage and daikon in the recipe below - I just cut it up and weighed it so that I knew how much salt to add. It turned out that this batch was about 1 cup too big to fit in the jar, but the little jar fermented just as well as the big one. I add the salt to the cabbage and daikon, let sit for a couple of hours for the liquid to release, then add everything else before stuffing into the jar. I ferment for two days at room temperature, which is just before I detect sourness. The kimchi is stored in the refrigerator where it will slowly develop acidity over weeks and months. In addition to salt level and flavorings, the sourness is another variable that can be adjusted to suit your preference. Just taste a sample daily.
I have tried a lot of different vegetables including carrots, turnips, beets, gobo, radishes, tops of daikon/turnip/radish, kale, mizuna, watercress, green/red/savoy cabbage, shiso, cucumber, eggplant, and more. They all work well as long as the salt level is consistent and the vegetables are fresh (organic is better) so that the naturally occurring bacteria has vitality. My salt percentage is a little lower here because the anchovy sauce and salted shrimp are included. If omitting fish products, umami could be added by using shiitake, konbu, wakame, shoyu, miso, or shiokoji.