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

Peel and mince garlic. Trim and cut scallions crosswise into 1-inch pieces; thinly slice one-quarter of the scallion greens. Trim and peel carrot; grate on the largest holes of a box grater. Roughly chop peanuts.

In a small bowl, whisk together sweet soy glaze, stock concentrate, half the Szechuan paste, half the vinegar, half the peanut butter, 1½ tsp sugar, ¼ cup water, and chili flakes to taste until smooth. (For 4 servings, use all the Szechuan paste, all the vinegar, all the peanut butter, 3 tsp sugar, and ⅓ cup water.)

Heat a drizzle of oil in a large pan over medium-high heat. Add pork*. Using a spatula, press into an even layer. Cook, undisturbed, until browned on bottom, 3-4 minutes.

Break up meat into pieces and continue cooking until pork is cooked through, 2-4 minutes more.

Add garlic and scallion pieces to pan with pork; cook until fragrant, 1-2 minutes.

Stir in sauce; cook until reduced and thickened slightly, 1-2 minutes.

Once water is boiling, add noodles to pot. Cook, stirring occasionally, until tender, 1-2 minutes. Drain and thoroughly rinse under cold water, at least 30 seconds. (This stops cooking and helps prevent sticky noodles.)

Add drained noodles, carrot, and 1 TBSP butter (2 TBSP for 4 servings) to pan with pork mixture. Toss until noodles are warmed through and everything is thoroughly combined, 1-2 minutes. (TIP: If needed, stir in water a splash at a time until noodles are thoroughly coated in sauce.) Taste and season with salt and pepper.

Divide stir-fry between bowls. Top with sliced scallion greens, peanuts, and remaining chili flakes to taste. Serve.