Bring a medium pot of salted water to a boil.

Pat steak* dry with paper towels; thinly slice against the grain.

In a medium bowl, combine garlic powder, half the cornstarch, half the soy sauce, a small pinch of salt, and pepper (all the cornstarch and all the soy sauce for 4 servings). Add steak; toss until coated.

Set aside until ready to use in Step 4.

Once water is boiling, add noodles to pot. Cook, stirring occasionally, until al dente, 5-7 minutes. Drain and set aside.

While noodles cook, wash and dry produce.

Cut tomato into ½-inch wedges. Core, deseed, and dice bell pepper into ½-inch pieces. Halve, peel, and cut onion into ½-inch-thick wedges. Trim and thinly slice scallion greens; cut scallion whites into 1-inch batons.

Heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add steak and cook, stirring occasionally, until a crust forms, 4-6 minutes (steak will finish cooking in the next step). Turn off heat; transfer to a plate. Wipe out pan.

Heat another drizzle of oil in pan used for steak over medium heat. Add tomato, bell pepper, onion, and scallion whites; cook, stirring occasionally, until browned and tender, 4-6 minutes.

While veggies cook, in a small bowl, whisk together sweet soy glaze, Sriracha, ketchup, stock concentrate, and ⅓ cup water (½ cup for 4 servings).

Add steak, noodles, and sauce mixture to pan with veggies. Cook, stirring constantly, until sauce has thickened and steak is cooked through, 1-2 minutes. (For 4, transfer veggies to a large bowl. Finish cooking steak, noodles, and sauce in pan as instructed; transfer to bowl with veggies and toss to combine.)

Taste and season with salt and pepper if desired.

Divide lo mein between plates and top with scallion greens. Serve.