Ask HN: Best way to get started in a different language

I've been a .NET developer for many years but would like to have experience in other languages/platforms so that I could apply for jobs requiring them. What's the best way to show exposure or experience? I realize I could do a personal side project but will that really be "good enough"? Are there companies that are willing to hire developers that don't have experience in a particular language and willing to see how long they take to pick it up? Also, I'm not looking to relocate so I would most likely be looking for a remote gig. Thanks.