Combine the chili-garlic sauce ingredients in a cup and whisk well to combine. Set aside.
Unwrap the udon noodles. Fill a large pan with hot tap water. Add udon noodles to this bowl and soak for a few minutes. Using a fork gently move the noodles around to separate. Drain the noodles. Rinse under cold water and drain again.
Transfer the drained noodles to a bowl and pour ¼ cup of the chili garlic sesame sauce. Save the rest.
Toss to combine. Set aside.
Place a heavy-bottomed pan over heat and add avocado oil. Once the oil is hot, add ginger-garlic and onions. Stir that for few minutes until the garlic becomes fragrant and onions are softened.
Add in sliced bell pepper, shiitake mushrooms and stir to combine. Cook for a minute or so.
Add Bok Choy and stir. Take it off the flame immediately. Do not cook the veggies after bok choy is added.
Pour the remaining sauce and toss gently.
Add the sauteed veggies to the pre-cooked noodles and toss gently to combine.
Serve yourself a full plate and enjoy!