Step 1: Cook the noodles according to package directions until al dente. Drain, rinse with cold water to prevent sticking, and set aside.
Step 2: In a small bowl, whisk together soy sauce, oyster sauce, brown sugar, and black pepper. Set aside.
Step 3: Pat steak slices dry with paper towels. Heat 1 tbsp olive oil in a large skillet or wok over medium-high heat. Add half of the minced garlic and sauté for 30 seconds until fragrant. Add steak and cook for 2-3 minutes per side, or until desired doneness. Remove steak from skillet and set aside.
Step 4: Add 1 tbsp olive oil to the same skillet. Add the remaining minced garlic and sauté for 30 seconds. Add shrimp and cook for 2-3 minutes, stirring occasionally, until pink and opaque. Remove shrimp from skillet and set aside.
Step 5: Reduce heat to medium. Add butter to the skillet and let it melt. Pour in the prepared sauce mixture and bring to a gentle simmer, stirring constantly for 1-2 minutes until slightly thickened.
Step 6: Add the cooked noodles to the skillet. Toss thoroughly to coat the noodles evenly with the sauce.
Step 7: Return the cooked steak and shrimp to the skillet with the noodles. Add 1/4 cup of chopped green onions and the sesame oil. Toss gently to combine all ingredients.
Step 8: Serve immediately, garnished with extra fresh green onions if desired.