Not having breef broth on hand, I substituted two beef bouillon cubes and two cups of water. Since I don't care for onions, I used fresh shallots which are much milder. I also used canned mushrooms which are just as flavorful. Although I drained off the fluid, the sauce was still thin but extremely tasty. We dipped pieces of bread in it and ate the rest with a spoon just like soup. Delicious! I enjoyed reading people's ideas about adding sour cream with the cream cheese and adding corn starch if desired.