I was browsing through a cookbook and the author suggested "their" version of a soup and it got me thinking, everyone should probably know how to cook a French onion soup the variables don't matter. You could use 1/4 cup of red wine vs 1/2 cup of white wine, I don't care. You could use beef stock vs. chicken stock, I don't care. The recipe is "SOOOOO" general all I care is that you make something resembling French onion soup that tastes good.
So, what are the recipes that, regardless of skill, everyone should know how to make?