Heat oven to 425°F.
Boil noodles for 3 minutes, drain, rinse with cool water, shake completely dry, then mix with sauce packets and set aside.
Place broccoli on a sheet pan and toss with olive oil and Momofuku Savory Seasoned Salt. Roast in the oven for 5 minutes, then remove. Turn the broiler on high and move your rack to the top of the oven.
Meanwhile, prepare your glaze by combining Momofuku Soy Sauce, honey, and Momofuku Chili Crunch in a saucepan over medium–low heat and stirring frequently for 5–7 minutes until slightly reduced. Toss about two-thirds of the glaze with your sliced beef and onions and reserve the remaining third.
Add noodles to the sheet pan and mix with broccoli, spreading the noodles all the way to the edges of the pan. Broil for 4 minutes. Remove from the oven, top with beef and onions, sprinkle with more Momofuku Savory Seasoned Salt, and broil for another 4 minutes. (All ovens are different, so monitor your noodles and beef carefully while they are broiling to ensure they are not burning.)
Top with remaining glaze and sesame seeds, if desired.
