Heat 2 Tbsp oil in a small pan over medium heat until shimmering.
Add the minced Tbsp of shallots and cook for 60 seconds or until fragrant.
Add the minced garlic and cook for another 30 seconds until fragrant.
Add the diced scallions and remove the oil from the heat. Mix in the Tbsp of chili crisp.
Chili Crisp Sauce
In a small bowl, add 2 Tbsp soy sauce, 1 tsp rice vinegar, 1 tsp maple syrup, ½ tsp sesame oil, 1 Tbsp chili oil, and 1 tsp umami seasoning.
Add in the chili crisp and mix all ingredients together. Season to taste. You can add an extra dash of oil to minimize the spiciness depending on your desired heat level. Set sauce aside.
Udon Noodles
In a large pot over high heat, add 7 cups water and 2 Tbsp. miso paste (if using). Bring to a boil.
Add the frozen udon noodle nests and boil until cooked through. Strain and set aside until ready. Reserve miso water for miso soup in the future, if desired.
Heat 2 Tbsp of oil in the bottom of the empty noodle pot. Add the shitake mushrooms and bok choy and sear the vegetables to desired tenderness.
Add the udon noodles back to the pot and toss with the chili crisp sauce.
Top noodles with sesame seeds and scallions. Serve with katsu chicken as desired.