For the potato and broccoli gratin, peel the potatoes and cut into slices. Clean broccoli and divide into small florets. Peel off thicker broccoli stems and cut into slices.
Peel onion and cut into fine cubes. Wash fresh thyme, shake dry and pluck leaves from stems.
Bring thyme, onion, whipping cream, water and clear soup to a boil in a saucepan. Cook potato slices in it over medium heat with lid on for about 10 minutes until tender.
Cook the broccoli for about 5 minutes. Lightly grease 4 small or 1 large gratin dish. Using a sieve ladle, scoop potatoes and broccoli out of the whipped cream and evenly distribute into the ramekins.
Melt the processed cheese in the whipped cream. Season with pepper, nutmeg and perhaps a little more salt. Pour cheese cream evenly over vegetables.
Bake the potato-broccoli gratin in the preheated oven at 200 °C for about 20 minutes until golden brown.