spring vegetable potstickers

INGREDIENTS

• 3 to 3 1/4 cups chopped spring vegetables (such as asparagus, favas, peas, lima beans or more) (I used 2 1/4 cups chopped asparagus from 12 ounces stalks plus 1 cup cooked favas from about 1 pound fresh in their pods)
• 1 tablespoon neutral cooking oil, such as safflower, canola or peanut
• 3/4 cup thinly sliced scallions (from about 3/4 of a bundle, about 3 ounces)
• 1 tablespoon minced ginger
• 1 clove garlic, peeled minced (if using garlic chives, omit)
• 1 cup (about 6 ounces) firm tofu, chopped small (see Note up top for alternative)
• 1/2 cup garlic or regular chives
• 1 teaspoon toasted sesame oil
• 1/4 teaspoon kosher salt, or more to taste
• 1 tablespoon cornstarch
• 1/2 cup water
• 50 round dumpling wrappers (most packages contain 50)
• 2 to 3 scallions (or, remainder of bundle used for potstickers), thinly sliced (use some in sauce, some for garnish)
• 1/4 cup rice vinegar
• 1/4 cup soy sauce
• 1 tablespoon regular or spicy toasted sesame oil
• 1 to 2 tablespoons neutral cooking oil
• 1/4 to 1/2 cup water