Sauce: In a small bowl combine 2 tbs tahini with 2 tbs peanut butter, 4 tbs soy sauce, 1 tsp crushed garlic and 1 tbs sugar. Mix well and set aside.
Vegetables: Grate 1 carrot and set aside. Remove the ends of 2 bok choi and rinse.
Pork: Cut pork belly strips into 1 inch pieces. Heat a pan to high heat and cook pork for 2 minutes, flipping halfway. Once it begins to crisp, deglaze the pan with 1 tsp soy sauce, 1 tsp water and 1 tsp sugar. Remove the pork. Add the bok choi to the pan for 2 minutes to flash fry, then remove.
Finish off: Cook udon as per packet instructions. Keep the udon water. Add the sauce into the pan from the pork and add 2 tbs udon water. Mix the noodles, sauce and water together to coat the noodles.
Serve: Plate up noodles, carrot, bok choi and finish with pork belly and a sprinkle of sesame seeds.