Boil 2 cups of water in a pot.
Add the buldak ramen noodles to the boiling water.
Cook the noodles for about 4-5 minutes until they are tender.
Stir in the buldak sauce and mix well.
Add optional vegetables if desired.
Cook for an additional 1-2 minutes to heat through.
Remove from heat and let it cool slightly.
Transfer noodles to a bowl.
Top with boiled egg, green onions, and sesame seeds.
Serve hot, garnished with chili flakes, if desired.