Cook the Book: Napa Cabbage and Shrimp Soup

Name: Cook the Book: Napa Cabbage and Shrimp Soup
Ingredients: 1 tablespoon canola or other neutral oil; 1 small yellow onion, thinly sliced; 1 heaping tablespoon dried shrimp, rinsed under hot water and chopped; 3/4 teaspoon salt; 1 tablespoon fish sauce; 6 cups water; 3 cups firmly packed sliced napa cabbage (1/4-inch wide ribbons); 1/2 pound small or medium shrimp, peeled and deveined; 1/8 teaspoon white pepper; 1 scallion, green part only, thinly sliced