Any small white onions will be fine.
That's shallot.
( Bartleby A dead man on vacation, Mon 14 Jan 2013, 9:17, 2 replies, latest was 13 years ago)

That's what I concluded
Although unless they're really tiny shallots you can't really put them in whole. Various sites also seem to disagree whether pearl onions and baby onions are the same thing.
( The Light in Chains don't touch the Pope's boner, Mon 14 Jan 2013, 9:20, Reply)

If you are worried about the size,
carefully remove the outer layer. You may be able to get a bag of pickling onions. They are normally quite small.
( Bartleby A dead man on vacation, Mon 14 Jan 2013, 9:24, Reply)

Pickling onions are a lot stronger tasting though
or so the internet assures me. There's a few places I can check on the way home from work, I'm not beaten yet.
( The Light in Chains don't touch the Pope's boner, Mon 14 Jan 2013, 9:27, Reply)

Post that gag, shame on you - read that gag, shame on me.

( Monty Boyce, My cheese game is strong, Mon 14 Jan 2013, 9:21, Reply)