It doesn't look in the least like a poached egg from my point of view, but it's got a yellow inside and white outsides...

I think I've got another batch coming that look rather like grass or oats: long thin stems with hanging flower heads. Having a mixed packet of unidentified small annuals is fascinating, but unfortunately I haven't been all that successful in identifying them; of course they tend not to be in my helpfully classfied 'identifying wildflowers' guide, and writers tend to assume you know what you planted in your own garden!