Bring a medium pot of salted water to a boil. Wash and dry produce.

Halve, peel, and thinly slice onion. Halve, core, and thinly slice bell pepper into strips. Using the tip of a spoon, remove and discard black gills from undersides of mushrooms; trim any large stems if necessary. Thinly slice mushrooms into strips (if strips are too long, cut them in half crosswise).

In a small bowl, whisk together honey, miso sauce concentrate, half the soy sauce, half the vinegar, half the Szechuan paste (use more for more heat), and ¼ cup water. (For 4 servings, use all the soy sauce, all the vinegar, and ⅓ cup water.)

Heat a large drizzle of oil in a large pan over medium-high heat. Add onion, bell pepper, and mushrooms; cook, stirring occasionally, until softened and lightly browned, 5-7 minutes.

Stir in Szechuan sauce mixture; cook, stirring occasionally, until sauce has reduced and slightly thickened, 1-2 minutes.

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

While noodles cook, roughly chop peanuts.

Add drained noodles to pan with veggies; toss until noodles are thoroughly coated in sauce. Taste and season with salt and pepper if desired.

Divide lo mein between shallow bowls. Top with peanuts and serve.