Heat the oil in a Dutch oven over medium-high heat. Add beef, and cook 5 minutes, browning on all sides. Add beef broth and next 9 ingredients (broth through black pepper), stirring to combine; bring to a boil. Cover, reduce heat, and simmer 45 minutes or until vegetables are tender, stirring occasionally. Discard bay leaf and thyme sprigs.
Combine 1/4 cup water, flour, lemon juice, and sugar, stirring well with a whisk. Add flour mixture to beef mixture, stirring constantly; bring to a boil. Cook 3 minutes or until slightly thick, stirring constantly. Remove from heat, and stir in parsley. Garnish with thyme sprigs, if desired.