What is something that you could practice for 1 hour max every day, for an entire year and by the end of the year you’d be an expert in?

Nothing of any consequence. Unless you are a super-mega-genius of Claude Shannon level or so. That’s only 365 hours. While the 10,000 hours thing is overblown, I’d say in many fields you can develop expertise if you’re reasonably smart in 2,000-20,000 hours. Some take even longer than that.

For 99.999999% of people, 365 hours is just not nearly enough to even be a really good amateur at something, much less an expert.