Trim base of each asparagus stalk and discard bottoms. Diagonally cut the spears into approximately 1-inch pieces.
Heat oil in medium saucepan over medium-high heat. Add shallots, garlic, salt and pepper and cook, stirring frequently, until shallots and garlic begin to soften. Add asparagus spears and continue to cook, stirring occasionally for two more minutes. Add broth, soy sauce, and sesame oil and bring mixture to a boil.
In a small bowl, combine cornstarch and water to make a slurry. Add to the soup and then add fish sauce. While briskly stirring, drizzle in the egg to create shreds in the swirling broth. Add the crab meat and stir. Continue to cook for another minute until the crab is heated through.
Divide into individual bowls and garnish with green onions.
Enjoy!