Hi,lbowan, there is a good program called Aimersoft DVD Creator,which can burn .mkv video file to a empty dvd disc easily and quickly.
Specifically,besides .mkv files,the program also supports avi,mp4, mpg, mpeg,3gp,wmv,asf,rm,rmvb,dat, mov,flv and even most HD formats like flv(Youtube),m2ts,tp and trp. And it supports the disc of DVD-r,DVD+r, DVD-rw,DVD+rw,DVD+r dl,DVD-r dl,DVD-ram,DVD–5 and DVD–9.
What's more,you can customize the video by trimming, cropping and setting background music,frame,button,menu template,slideshow transition effect.
If you wanna learn more info about it,visit the link-> http://www.dvd-creator.org/dvd-creator/index.html#173