In a large pot of salted boiling water, place pasta and cook for 8 to 10 minutes, until pasta is al dente. Drain.
In a large frypan, saute garlic in butter over medium heat. Stir in the cream, chicken stock and powder. Add Parmesan cheese, salt and pepper. Add cornflour (adjust amount to thicken sauce to your liking). Simmer all together for about 20 minutes.
Once sauce is cooked and thickens, add broccoli and artichoke hearts, stir all together and cook for another 2 to 3 minutes.
Put cooked pasta in a large bowl, pour sauce over pasta and toss to coat and mix. Then add the chicken pieces and mix all together.