A bullion cube is a small block of compressed, concentrated seasoning used to add flavor to soups, stews, and sauces. It is made by reducing stock or broth until it becomes a solid cube for convenient storage and usage. Full definition
Yes, the heavy creamy would usually be way too rich for me too, which is why in this recipe I thin it out with 1 cup of chicken broth (made out of chicken bullion cube + pasta water)-- I hope you did not miss that step somehow! (juliasalbum.com)
I don't use oil, so I substituted veggie broth for that and ran out of bullion cubes, so used Mrs. Dash. (vegkitchen.com)
A shortcut would be to make a quick veg stock, don't add any salt, and then throw in a couple vegetable bullion cubes. (onebitevegan.com)