Mix the ingredients for the marinade in a bowl.
Shred the beef thinly and put in the marinade for 15 minutes, ideally 1 hour.
Cook the noodles according to the instructions on the package. Drain, rinse in cold water and cut them in half so they are not too long.
Cut the squash in slices, peel and thinly slice carrots and garlic, slice the leek and shred the sweet pepper.
Heat the oil in a wok and fry the vegetables for a few minutes on high heat, they should soften slightly. Set aside.
Stir-fry the meat with the marinade over high heat until nicely browned. Stir in noodles, vegetables and water if needed. Add more soy/coconut aminos if needed.
Garnish with sesame seeds and thinly sliced chili.