Heat oil in a large Dutch oven over medium heat; add onion and garlic. Cook 9 minutes or until lightly browned, stirring occasionally. Add flour, thyme, and pepper; cook 2 minutes, stirring constantly. Gradually add broth; bring to a boil, stirring occasionally. Reduce heat; simmer, uncovered, 10 minutes, stirring occasionally. Stir in parsley.
Place bread slices on a baking sheet. Sprinkle 1 tablespoon cheese over bread slices. Broil 1 minute or until cheese melts.
Ladle soup evenly into bowls. Serve with cheese toast.