Wash and dry produce.

Trim and thinly slice mushrooms (skip if your mushrooms are pre-sliced!). Peel and mince or grate garlic. Trim and thinly slice scallions, separating whites from greens.

Pat steak* dry with paper towels; season generously all over with salt and pepper. 

Heat a large drizzle of oil in a large pan over medium-high heat. Add steak and cook until browned and cooked to desired doneness, 3-6 minutes per side.

Turn off heat; transfer to a cutting board to rest for at least 5 minutes. 

Heat a drizzle of oil in a medium pot (large pot for 4 servings) over medium-high heat. Add mushrooms and cook, stirring occasionally, until beginning to soften, 2-3 minutes. 

Stir in garlic and scallion whites. Cook, stirring frequently, until veggies are tender, 2-3 minutes.

Stir half the soy sauce (all for 4 servings) into pot with veggies. Cook, stirring, until liquid is mostly evaporated, 30 seconds.  

Stir in 4 cups water (7½ cups for 4), mushroom stock concentrates, and pork ramen stock concentrates. 

Bring to a boil, then add noodles. Cook, stirring, until just tender, 1-2 minutes. 

Turn off heat. Add bok choy and napa cabbage and truffle butter. Stir until butter has melted and veggies are wilted, 30-60 seconds. 

Thinly slice steak against the grain.

Divide noodles and broth between bowls. Fan steak over top. Garnish with scallion greens and sesame seeds. Sprinkle with truffle seasoning to taste. Serve.