Garlic Green Beans with Crispy Ground Beef

Name: Garlic Green Beans with Crispy Ground Beef
Ingredients: 3 tablespoons canola oil, divided; 8 ounces 90%-lean ground beef; ½ teaspoon salt, divided; 2 tablespoons rice vinegar; 2 tablespoons Shaoxing rice wine or dry sherry; 1 tablespoon toasted sesame oil; 1 ½ teaspoons fish sauce; 1 teaspoon granulated sugar; ½ teaspoon ground white pepper; 1 ½ pounds green beans, trimmed and halved; ½ cup sliced scallion whites, plus sliced scallion greens for garnish; 6 cloves garlic, minced; 2 teaspoons grated fresh ginger