Adjust rack to middle position and preheat oven to 375 degrees. Bring a medium pot of salted water to a boil (large pot for 4 servings). Wash and dry produce.

Quarter cabbage lengthwise, keeping stem and core intact. Trim and thinly slice scallions, separating whites from greens. Roughly chop cashews.

In a small bowl, whisk together miso sauce concentrates and ¾ cup water (1½ cups for 4) until smooth.

Heat 2 TBSP butter (4 TBSP for 4 servings) and a drizzle of oil in a large, preferably ovenproof, pan over medium-high heat. Add cabbage, cut sides down. Cook until dark brown and beginning to soften slightly, 3-4 minutes. Flip cabbage to second cut side; cook until dark brown, 3-4 minutes more.

Add 1 TBSP vinegar (2 TBSP for 4) to pan. Cook, undisturbed, until vinegar has mostly reduced, 15-20 seconds.

Stir in miso mixture (reserve bowl); bring liquid to a boil. Once boiling, turn off heat. (If your pan isn’t ovenproof, transfer cabbage and liquid to a baking dish now.)

Carefully transfer pan to oven and bake on middle rack until cabbage is tender and liquid has reduced, 20-25 minutes.

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

Drain noodles and rinse under cold water, 30 seconds. Shake off excess water and set aside. Reserve pot.

Meanwhile, in bowl used for miso mixture, whisk together Vidalia onion paste, soy sauce, chili sauce, remaining vinegar, and ¼ cup water (½ cup for 4 servings) until smooth.

Heat a large drizzle of oil in pot used for noodles over medium-high heat. Add carrots and scallion whites; lightly season with salt and pepper. Cook, stirring occasionally, until carrots begin to soften slightly, 1-2 minutes.

Reduce heat to medium. Add garlic powder and cashews. Cook, stirring, until garlic powder is fragrant, 30-60 seconds.

Add drained noodles, soy-chili sauce, and 1 TBSP butter (2 TBSP for 4 servings) to pot with carrot mixture. Cook, stirring, until butter has melted and noodles are thoroughly coated, 30-60 seconds. Taste and season with salt and pepper if desired.

Divide carrot and cashew lo mein between shallow bowls; top with braised cabbage. Spoon as much miso butter sauce from pan over cabbage as you like. Garnish with crispy fried onions and scallion greens. Serve.