Easy Gan Bian Si Ji Dou (Sichuan Dry-Fried Green Beans)

Crush half of Sichuan peppercorns in a mortar and pestle into a rough powder. In a medium skillet, heat 2 tablespoons oil, remaining whole Sichuan peppercorns, and dried chiles over medium-low heat, stirring frequently, until sizzling and aromatic, about 2 minutes. Add garlic, ginger, scallions, and mustard root and cook, stirring, until aromatic, about 1 minute. Remove from heat and set aside.

Adjust rack to as close as possible to broiler and preheat broiler to high. In a large bowl, toss green beans with 1 tablespoon oil and season with salt and white pepper. Arrange in a single layer on a foil-lined rimmed baking sheet or broiler pan. Broil until beans are blistered and very lightly charred, 2 to 5 minutes depending on strength of broiler. Return beans to bowl.

Using a rubber spatula, transfer Sichuan peppercorn mixture to bowl with beans. Add sugar and remaining crushed peppercorns. Toss to coat the beans thoroughly in the mixture and season to taste with more salt and white pepper if desired. Serve immediately.