Unity / Mono scripts not available in VS Code intellisense

When I found Unity supports Visual Studio, I switched to Windows to take part in all its glory. Now I'd like to have the option to use Visual Studio Code and Unity back on OSX. The problem is that while it looks like I have everything setup, intellisense doesn't show anything after the first dot.

I see the flame on the bottom of the screen and it recognizes C#.

What could I be missing?