Combine all ingredients with a hand whisk or stand mixer until the sauce has thickened to your desired texture.
Although it can be served immediately, it's best after sitting overnight for the flavours to combine fully.
Sweetened Condensed Milk Brand: I used the Compliments brand of sweetened condensed milk. The Eagle Brand is a good substitution. They both have 11g of sugar per tablespoon. Keep in mind different brands of sweetened condensed milk may have different sugar contents - making them sweeter or less sweet than this one. Adjust with more vinegar/sugar to get the sauce to your desired sweetness.