Pour sweetened condensed milk into a 1-quart microwave-safe bowl.
Microwave on MEDIUM for two minutes.
CAREFULLY remove from microwave and whisk. (I did this using two oven mitts to move the bowl, un-mitted my left hand to hold the whisk, and used my right hand, still in the mitt, to steady the bowl as I whisked.).
Return to microwave and repeat, heating two minutes at a time and whisking until mixture looks curdled.
Remove from microwave and whisk again for a dulce de leche sauce.
For a candy texture repeat cooking and stirring one more time.