Awesome SA! Congrats are in order, for sure.
We kept a male green mandy for about 8 years or so, and it ate everything that wasn't red-hot or nailed-down. The key with these fish is to get them to RECOGNIZE all of the good things we offer them as food, but once they try one or two foods, they usually fall right in line, so your method of starting with the roe is a good way to go. Live blackworms is another good food that tends to excite mandies.