Place a frying pan on medium heat. Add in your oil followed by the chilli flakes, sesame seeds, chilli powder, and garlic. Mix thoroughly and then add in your ground beef and stir fry for 5 minutes until turned brown.
Meanwhile, make your sauce by combining soy sauce, rice wine vinegar, sesame oil, sugar, and peanut butter. Mix until smooth.
Pour in your soy sauce mixture followed by 150ml water (or stock). Give everything a good stir and reduce to low. You should have a saucy ground beef spicy situation. Taste and then season with salt and pepper based on your preference. Cook for a further 5 minutes while your noodles cook.
Cook your egg noodles to packet instructions in salted boiling water.
Once you've drained your noodles, divide them between four bowls and evenly top with your ground beef sauce. Top with sliced cucumber, chopped cilantro, and green onions. Mix thoroughly and enjoy!