So easy and such a classic!
Add all ingredients to a jar and shake.
Go by taste: Use just a touch of sugar if going savory. Omit the onion and use a higher amount of sugar if serving with fruit.
Onion can be easily juiced by grating a small amount, placing it in the corner of a basic, clean towel, and squeezing.
Taste and adjust seasonings. Will separate easily, so if passing at the table, do so in a jar that can be shaken.