Heat oil in a large soup pot over medium-high heat. Cook the ground beef, shrimp, ham, mushrooms, and leeks in the oil until the ground beef is browned, about 10 minutes. Pour in 8 cups water and bring to a simmer; cook for 10 minutes.
Stir the tofu and creamed corn into the soup. Whisk the cornstarch into 1 cup water; stir into pot. Bring to a simmer; cook until the soup has thickened, about 5 minutes. Slowly stir egg whites into thickened soup until they firm into ribbons.