Yeah, pretty easy to do. The Mac Mini should show up as a shared computer in the Finder window. Click Share Screen and voila! Run my Mini totally headless, and just go from my MacBook. Can also do this from an iPad, iPhone or Android phone (with the appropriate software installed), but I haven't messed much with that. I also use the Public Folder of computers set up this way to exchange files back and forth.
What I haven't done and would like to do is to see if this screen sharing can be done with the Mac Mini hardwired to the network via Ethernet and my MacBook using the wireless network. Keep meaning to look into that. Right now it is all over WiFi.