the roots are still covered and there the stem snapped off right at the dirt levelTrim the stem down to the closest node to tidy it up and you're left with a topped plant essentially. How many nodes do you have left?
here is pictures of both partsOh I thought by bit of stem you had some nodes!
I had some outdoor plants that were eaten by something and it revegged after a few weeks so you could hold out for that but you'd be better off to start again from scratch unless you have space to wait and see.