Slice shiitake mushrooms and snow peas. Thinly slice shallot and finely mince garlic.
Make the sauce by mixing all the sauce ingredients in a small bowl until combined. Taste and adjust seasonings to your preference if needed.
Heat up 1/2 tbsp olive oil in a nonstick skillet over medium-low heat. Add shallots and garlic and stir fry until fragrant.
Add shiitake mushrooms and snow peas. Cook and stir for about 1 minute, then add 1 tbsp of oyster sauce. Stir until combined and cook for another 2 minutes or until desired doneness. Turn off the heat.
Meanwhile, cook udon noodles according to package instructions.
When noodles are done, remove them with a slotted spoon (reserve the water for the soft boiled egg) and transfer udon to the skillet with the vegetables. Add sauce and stir until all the udon is coated in the sauce. Add a splash of water if needed.
Make soft boiled egg by bringing the pot of water back to a boil. Gently and slowly add the egg to the water. When the water starts boiling again, set a timer for 7 minutes.
As the egg is cooking, prepare a bowl of ice water bath.
As soon as the timer goes off, remove the egg using a slotted spoon and immediately place it in the ice water bath.
Peel the egg and cut it into two halves.
Transfer udon to the serving plates and top each one with half a soft boiled egg. Top with a sprinkle of sesame seeds. Enjoy!