pert:
Yes, you can use an Uno as an "Arduino as ISP" to burn the bootloader to an Uno.You can use it to burn the bootloader to any AVR microcontroller-based Arduino board. In fact, I'm quite surprised that you didn't find the official Arduino as ISP tutorial that shows just this:
https://www.arduino.cc/en/Tutorial/ArduinoISP
Thank you. I was pretty sure is would work. I too am surprised I didn't find it, but I have it now, so thanks.