Place the salmon in a shallow dish.
In a saucepan, mix the soy sauce, brown sugar, mirin, and cooking sake. Heat over medium heat until sugar is dissolved.
Remove half of the sauce and pour it in with the salmon. Marinate for 30 minutes in the fridge.
Leave the rest of the sauce in the pot and turn the heat to medium high. Once boiling, add the cornstarch slurry. Whisk for 2-3 minutes, until the sauce has thickened. Remove from heat and set aside.
After marinating, remove the salmon and set it on a baking tray. Preheat oven to 325°F. Bake the salmon for 10-12 minutes, until it reaches 130°F.
Heat water to a boil in a pot. Cook the soba noodles until tender (according to the package instructions). Drain. Immediately sprinkle on the sesame oil and toss the noodles so they don’t stick together.
In a skillet, heat the cooking oil. Add the sugar snap peas and bok choy. Saute for 3 minutes. Add the soba noodles, teriyaki sauce, and green onions. Toss it all together.
Serve with remaining teriyaki sauce poured over the top and sesame seeds for garnish.