Decided some time ago to start making my own kimchi, which is about as essential as rice. If there is no other banchan, kimchi is the very least to have. The great thing about kimchi is that there are different types of kimchi for all of the seasons.
Everyone does theirs a little differently to taste, but the basics are napa, cut and salted and drained, then pitched with ground red pepper, sugar, green onions, lots of garlic. I've seen fish sauce and other vegetables included. A few days sitting out, covered, will let it ferment.