Gravy is needed sometimes, but we needn't make it mostly salt. Here is an option that can top any dish. It is a combination of a standard roux-based gravy (but without a stock), and a Bearnaise-like emulsion.
I find that it is not common in our house to have soup stock. The soups I make do not have stock in them, including onion soup and split pea soup. Can-based or bouillon-based stocks have an incredible amount of salt in them, along with other nastiness.
Typically, the ingredients (of bouillon cubes) consists of salt, hydrogenated fat (trans-fats), monosodium glutamate (MSG), flavor enhancers, and flavors. --Bouillon cubes - Wikipedia
- Egg yolks
- Balsamic vinegar
- Olive oil
- Clean, dice, and cook onion and mushrooms with butter
- Remove mushrooms and onion from pot and set aside
- Add flour to butter, stir to make a roux, set aside
- Emulsify egg yolks, add olive oil, add balsamic vinegar
- Whisk emulsion into roux
- Slowly whisk in blended onion, mushroom, and water mixture