For the vegetable spaghettini, cook the pasta in plenty of salted water until al dente, strain and rinse.
Chop the onion. Wash leek, zucchini, kohlrabi and cut into bite-sized pieces. Drain and dice tomatoes. Heat some olive oil in a pan and sauté the vegetables in it, add pasta, press in garlic, add whipping cream and season. Arrange the vegetable spaghettini in a plate with Parmesan cheese and serve.