Combine the oyster sauce, fish sauce, and hoisin on a plate. Use a fork to mix the ingredients together, then dredge the steak or steaks back and forth to coat on both sides.
Heat a large skillet to medium-high heat with a drizzle of oil, and cook the steaks for 3-4 minutes on each side until medium-rare and browned on the edges. Remove from the heat, and let rest to cool. In the same hot pan, add any leftover steak sauce and the beef stock. Stir to combine and deglaze the pan, then turn off the heat.
While the steak is cooking, make the drizzle by combining the chili sauce, hot sauce, and vinegar. Taste, and add more hot sauce if you can take it, or more of the other two ingredients if the sauce is too spicy for you.
When the steak has cooled slightly, thinly slice it against the grain.
To the pan with the cooled beef sauce, add the noodles, scallions, bean sprouts, and half the peanuts. Toss to combine, and taste - add a bit more beef broth, fish sauce, or hoisin if you'd like.
To serve, top the noodles in bowls with some of the steak, extra peanuts, sesame seeds, and lime wedges. Drizzle with hot sauce, and enjoy!