Run some boiling water through the drain then chase it with baking soda and vinegar, preferably you have some way to stopper the sink after adding the vinegar and confine the chemical reaction to the drain, give it maybe a hour and then dump in more boiling water. Ideally you want to do this kind of stuff before it becomes completely clogged because it’s a lot harder to remediate it without physically taking the pipes apart or running a drain snake through it.