Looks like a weed I've seen several times before. I don't know what it's called. It doesn't look like the pictures of tomatillos I googled because unlike the tomatillo it's neat and orderly around one central stem.
Maybe lambsquarters? But that picture and the ones I remember look slightly different from lambsquarters on google images so I'm not sure. If so it would be both a weed and a vegetable, since lambsquarter is an edible wild green in the same family as spinach and beets. But I wouldn't bank your stomach on it until you make sure.