Hi @bslatky and welcome to our little corner of the web! I don't have any personal experience running OpenEMU, but I'm curious what version of jzIntv you're using. Just recently, a new release was announced, and is available here. You'll definitely want the 64-bit downloads, as newer Macs won't allow 32-bit apps to run any more. You may also need to get the appropriate version of SDL onto your system.
As to why the ROM won't load in OpenEMU, a few questions come to mind... Generally, Intellivision ROMs are distributed in two formats (there are variations of them, and another out there, but let's set that aside). The two are .rom (a single-file format), and .bin format, which almost always also requires a companion .cfg file. (Other file extensions have been used in place of .bin as well.)
So -- which format is that ROM in?
Furthermore, Intellivision emulators require two "OS" ROMs as well -- delivered as EXEC.bin and GROM.bin. These can only be obtained legally by owning one of the various ROM collections sold by Blue Sky Rangers, Inc. (nee Intellivision Productions) - though *cough* *cough* there are places that have them for download.
Some emulators include a public domain version of those two ROMs, which are incomplete reproductions. It's usually pretty obvious because the standard font in the traditional title screens will look different. If you attach a screen shot from OpenEMU it will be obvious if the "mini-EXEC" and "mini-GROM" are in use.
Hope you find success in getting SuperChef BT going - it's a really fun expansion of the already incredible original.