Combine the water, salt, thyme, bay leaf and olive oil in a soup pot and bring to a boil. Reduce heat to a simmer and squeeze in the garlic. Add the green beans and simmer, uncovered, for 10-12 minutes. Adjust seasonings. Beat the egg in a bowl and ladle some soup into the egg, stirring. Return to the pot, stirring all the while. Add pepper. Let simmer a few minutes, tasting to make sure the flavors blend. Serve topped with parsley and/or croutons.