Bring a large pot of salted water to a boil. Wash and dry produce. Trim scallions and cut whites into 1-inch pieces; thinly slice greens. Peel and mince or grate 1 clove (for 2 person) or 2 cloves (for 4 person) of garlic.

Heat a drizzle of cooking oil in a large, preferably nonstick pan over medium-high heat. Add beef; using a spatula, press into an even layer. Season with a big pinch of kosher salt and black pepper. Cook undisturbed until browned on the bottom, 2-4 minutes. If there's excess grease, carefully pour it out. Add 8 oz of red cabbage and carrot mix and scallion whites; cook, stirring occasionally and breaking up meat into pieces, until veggies are browned and tender and beef is cooked through, 2-4 minutes more. Stir in 1 TBSP (for 2 person) or 2 TBSP (for 4 person) of pork ramen stock concentrate, 4 TBSP (for 2 person) or 8 TBSP (for 4 person) of sweet soy glaze, and 1/4 cup water (or 1/2 cup for 4 servings). Bring to a simmer and cook until thickened, about 1 minute. Turn off the heat.

Once water is boiling, add 9 oz (or 18 oz for 4 servings) of lo mein noodles to the pot. Cook, stirring occasionally, until al dente, 5-7 minutes.

While noodles cook, in a small microwave-safe bowl, combine garlic, sesame seeds, half the chili flakes, 1 tsp oil (or 2 tsp for 4 servings), and a pinch of salt. (Use fewer chili flakes if you prefer less heat.) Cover tightly with plastic wrap and microwave until fragrant, about 30 seconds.

Once noodles are al dente, drain and transfer to the pan with the beef mixture. Toss until thoroughly coated. Taste and season with salt and pepper if desired.

Divide beef lo mein between bowls. Drizzle with garlic chili oil and sprinkle with scallion greens. Serve.