As long as you keep the amount the same - 1 cup pearl onions = 1 cup of your onions.

Since yours are likely larger than pearls it will mean far less onions total. Or you can chop yours to pearl size. ;)

Instead check the NCHFP recipe that calls for sliced onions and see how the total amounts differ from the one you are using. You can leave out the peppers in it if you don't want them. Low acid food ingredients can be reduced, they just can't be increased.

Dave

Here is a link that might be useful: Pickled Cauliflower

There are cocktail onions (in little jars) that are very small as well as frozen onions too. I also see white boiling onions sold loose, so I pick out most of the smallest ones in stores. If I have neither, I just thinly slice regular onions, or use sliced red onions for a bit of color. My cauliflower also has cukes, sometimes sliced carrots, a few sweet red pepper slices, and sweet vinegar brine, the same as a sweet mixed pickle.