It's bland bread, with a slightly crispy yet still bland outside, surrounding a bland omelet of bland cheese mixed with bland vegetables, like a sort of bland burrito with no outer cracks, or a huge bland pastry bun with an apparently solid exterior! Though if Merrin only broke off a sufficiently little bit, she'll just get the outer bland bread part.
(It's a kind of food that can dry out, so Esta made it in a form factor that put the moist parts inside.)