For the chicken soup
Place a pot over medium heat and add the olive oil. Add onion, leek, celeriac and carrot. Season with salt and sauté, stirring often until the celeriac and carrot begin to soften but remain crisp. Add garlic and as soon as it releases its aroma, add the stock, bring to a boil and immediately reduce the heat. Add asparagus and zucchini, season with salt and simmer until the vegetables are tender, taking care not to overcook. Add the spinach and as soon as it has wilted add the remaining ingredients. Taste for seasoning.