This is a jukugo word that uses the on'yomi readings of the kanji. You learned the reading for the second kanji but not the first one yet. Here's a mnemonic to help you:

The army said it would provide you with some army provisions. That's great! You go to the drop site where the provisions are, and you see the provisions. "Heyo! It's roe!" (ひょうろう) you say out loud. You're pretty happy that your provisions consist of tons and tons of roe!