1) Peel the tough, fibrous layers from the outer celery ribs. Split the ribs lengthwise and cut into 5- to 7.5cm long pieces. Chop 2 tablespoons of the celery leaves, save the rest for other uses; they are great in salads.
2) Put the celery, broth, olive oil, garlic, celery seeds, and thyme in a medium skillet. Season with salt and pepper. Bring the liquid to a boil over high heat, and then adjust the heat to maintain a gentle simmer. Place a circle of parchment paper directly on the vegetables or set a lid slightly ajar on the skillet. Cook until the celery is tender but not mushy, about 15 minutes. Transfer the vegetables to a serving dish, and reduce the cooking liquid to a saucy glaze. Remove the thyme sprig, and pour the cooking liquid over the celery, sprinkle with the cheese, and serve.