Fried Garlic Chips: Take out the large cloves from the head of garlic. Thinly slice them widthwise and remove the green core. You can omit this step; however, the core will come out easily while frying and burn quickly, which will result in darkening the oil color. Therefore, if you have time, I recommend removing it. Add the oil in the frying pan over medium-low heat. While oil is still cold, slowly fry the garlic slices until golden brown, then dry on paper towel. Once cool, store them in an airtight container. Transfer the garlic infused oil into a small jar to use in other recipes.
Gather all the ingredients. Please note that you will need to cook my Oxtail Broth and Meat first. Put the oxtail broth in a large stockpot (transfer from your Instant Pot if making on the same day). Reheat the broth and keep it on low simmer. Skim if necessary.
Add water in a medium saucepan and bring it to a boil. Once boiling, add katsuobushi.
Lower the heat and keep on low simmer for 10-15 seconds and turn off the heat. Set aside to steep for 10-15 minutes.
Strain the katsuo dashi over a fine mesh sieve into a bowl/measuring cup.
Add the katsuo dashi into the oxtail broth. Now you have oxtail katsuo dashi.
Add kosher salt, soy sauce, and white pepper. Taste the soup and see if you need to adjust. Keep it on low simmer until you’re ready to serve.
Chop green onions. Bring a large pot of water to boil for udon noodles. My favorite udon is the frozen Sanuki Udon. Cook the frozen udon noodles in boiling water for 1 minute (no need to defrost). If you use dry noodles, follow the package instructions.
Pick up the udon noodles and transfer to the serving bowl or donabe. Add the oxtail meat and the soup. Top the udon with green onions and fried garlic chips. If you like it spicy, add your favorite chili oil or hot sauce.
You can keep the leftover soup in an airtight container and store in the refrigerator for up to 3 days and in the freezer for a month. Cook noodles before serving.