Pour stock into a wide pot. Clean, peel, wash and slice the parsnips and add to the stock. Bring broth to a boil and simmer for 15-20 minutes.
Separate eggs, chill egg whites. Mix ricotta, sour cream, lime zest and juice, 75 g sugar, egg yolks, 1 egg and pudding powder. Sprinkle the shortcrust pastry base with almonds, add cream and smooth it down. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) on the lower rack for 35-40 minutes
Wash thyme and shake dry and, except for 4 stems for garnishing, strip leaves from the stems. Add the onions, thyme leaves and zucchini to the soup about 3 minutes before the end of the cooking time. Season to taste with salt.
Arrange the soup with bacon in bowls, sprinkle with ground pepper and garnish with sprigs of thyme. Roasted baguette tastes good with it.