Heat the butter in a large saucepan. Add the onion, garlic, leek, salt and pepper and cook for 3-4 minutes. Add the zucchini and carrots and simmer for 10 mins. Add the chicken broth (water with bouillon) and thyme and bring to a boil. Add the pasta nests and chicken and cook for 4 mins until the pasta is cooked. Serve hot in soup bowls.