The phrase "additional thyme" refers to getting more time to do something or having extra time beyond what was originally planned or expected. Full definition
Add more fresh pepper and a squeeze of fresh lemon juice, and garnish with additional thyme and fresh parsley before serving, if desired. (healthygreenkitchen.com)
Serve hot with pan juices, garnished with additional thyme if desired. (acalculatedwhisk.com)
Sprinkle with additional thyme, if desired. (myrecipes.com)