In a small bowl, mix together the soy sauce, oyster sauce, sesame oil, garlic, ginger, brown sugar, rice vinegar, and cornstarch until well combined. Set aside.
Heat two small skillets over medium-high heat and add a tablespoon of butter or oil.
Arrange half of the thinly sliced steak in each skillet around the edges of the pan, leaving the center empty. Season each portion of steak with half of the chili powder, salt, and black pepper.
Place half of the cooked udon noodles in the center of each skillet.
Pour the prepared sauce over the steak, making sure it's evenly coated.
Let everything sizzle and cook together, stirring the steak occasionally to ensure even cooking, about 6 to 8 minutes, until the steak is fully cooked and the sauce has thickened.
In a separate pan, fry an egg to your desired doneness.
Top the udon and steak with green onions, sweet corn, and the fried egg. Finish with extra black pepper.
Serve hot and enjoy!