cook spaghetti, drain, and set aside.
while spaghetti is cooking, saute onions and garlic in butter and oil in large skillet for 2-3 minutes
add artichokes and tomatoes to skillet and cook for 8-10 minutes
reduce heat to low and stir in cream and chicken broth. add salt and pepper and cook over low heat until heated through
place pasta in large bowl and sprinkle with parmesan cheese. pour sauce over the top and add herbs.
toss lightly to combine and coat, add more chicken broth if sauce seems too thick