In a small bowl, stir together the ⅓ cup water, 2 tablespoons of the vinegar, soy sauce and sugar. In a second small bowl, stir together the 2 tablespoons water and the salt. In a third small bowl, combine the garlic, ginger, pepper flakes and minced scallions.

In a large skillet over medium-high, combine the broccoli, salt water and 2 tablespoons of the peanut oil. Cover and cook for 1 minute; the water should reach a simmer.

Uncover and cook, stirring occasionally, until the broccoli is crisp-tender and browned in spots, 8 to 10 minutes. Transfer to a large plate.

Return the skillet to medium-high, add the remaining 1 tablespoon peanut oil and the garlic-ginger mixture.

Cook, stirring, until fragrant, 10 to 15 seconds. Add the soy sauce mixture and simmer, stirring and scraping up any browned bits, until slightly reduced, 2 to 3 minutes. Return the broccoli to the skillet and stir to coat.

Off heat, stir in the sesame oil, remaining 1 tablespoon of vinegar, and ½ teaspoon of the Sichuan peppercorns. Taste and add more peppercorns, if desired. Serve sprinkled with the sliced scallion greens.