Peel and dice the onion. Wash the zucchini and cut into small pieces.
Heat the oil in a saucepan, sauté the onion until translucent, add the zucchini and fry briefly. Pour in the vegetable stock and cook for about 10 minutes. Then puree the whole thing with the hand blender. Fold in the cream cheese. Fold in the diced ham. Add the herbs. Season to taste with salt and pepper.
Cook the tagliatelle as instructed and serve with the sauce.