A mustard/turnip/radish of some type? Eating from your own garden means that you are going to have to drop the supermarket aesthetics as to shape, color, form, perfection, and blemishes or insect damage. A radish with a twinned
root is never going to make it to the supermarket -- but it's still perfectly edible. Collards with some bug holes are not going to make it either -- even though it makes no difference if your ultimate use is to chop it up and cook it with some onions and hog jowl. And if you saved seed from last year and have some crossed plants, well, who know what they are going to look like.
Since we have narrowed them down to being some variety of
Brassica, just pinch off a bit off and taste it. If it's mustard, you'll know
real quick.
If it's a more mild relative from the cabbage side of the family, you can decide if it would be good raw (like in slaw), or if it's a little tough, maybe it needs to be chopped up and fermented (you can sauerkraut almost any brassica), or you can put it in the slow cooker for some long term breakdown.
Broccoli has a typical story of modern food mass marketing. What gets served in restaurants and offered in the frozen food or fresh veggies section is the first heading of the plant, preferably mostly crown, with little stalk. Most of the stalk is thrown away -- it's great to put into soup or shredded into stir-fry. Leaves are also thrown away -- unless you are Italian, inwhich case the leaves make a nice addition to minestrone. The little secondary headings -- broccoli raab -- used to get turned under. But now they can be an upscale yuppie vegetable, lightly steamed and served cold with some vinaigrette. If you've ever seen a broccoli field after harvesting, you will be amazed at how little biomass actually ends up at the grocery store and how much of it gets fed to cows or pigs, if it isn't just turned under.
If it looks nice, take a taste. Then you can think about what would be the best way to prepare it. If it doesn't look nice, it's still good rabbit/pig/goat/guinea pig fodder. Whatever they don't eat, boil up until it is soft and throw it in the
chicken pen.
Chickens will eat just about anything.
Maybe with a little more time, the wife will be a little more adventurous with plants from the garden. Don't be afraid to experiment. Try them in all sorts of recipes. Except for trying to make bread-and-butter pickles out of kohlrabi; I tried that a while ago and that wasn't a keeper.