Dice all the onion into a small uniform dice. Add the butter to a frying pan and turn on the heat to get it melting. Add the onion and a good couple pinches of salt. Cook at medium and low alternating the heat as needed to avoid burning the onion but giving it a nice color. It will take about 45 minutes to an hour to reduce the onion to 1 cup of dark dark brown onion. Make sure you are constantly scraping the pan to keep all the browned bits in the food and not stuck to the pan. Remove from heat.
Mix the mayo, sour cream, and yogurt. Stir in the onions once slightly cooled. Add in the chives, garlic, salt, pepper, gochugaru, and the lemon juice and stir. If you like, add in a few shakes of hot sauce.
Refrigerate for at least an hour. After an hour, stir it up and taste it. Adjust seasonings as needed by adding some more hot sauce, lemon, salt or pepper. If it is too thick you can add a little more lemon juice, mayo, yogurt, or sour cream. Serve with potato chips!