This photo is called "turnips"
Photografer is Saidunsaid, and you can find more of her photos here.
Turnip seems to be a dream crop for the indoor gardener, it's fast growing and both root and leaves can be eaten. It prefers light soils, but I suspect it can grow almost everywhere. It's a coldclimate crop, which makes it most popular on the nortern parts of the globe.
Since I've found cooking tips both for root bulbs and leaves I conclude that they both are tasty. The plant contains a lot of vitamin C, as well as B2, B1, B6, folat and niacine. The leaves are the most concentrated and contains a comparable large amount of protein (to be a plant of that kind, that is).
The downside is that turnip contains oxalat, which - if you eat a lot of it - crystallize in the body and causes different kinds of health problems. What concerns me more is that turnip contains goitrogens that surpress the thyroid function. Any person with diagnosed but untreated thyroid problems should avoid turnip. Since many of our old cultivated crops do contain oxalats (spinach and rubarb) or goitrogens (most cabbages) I suspect that these 'back sides' can be balanced by a varied diet and by drinking an healthy amount of water (1-2 litres or 1/3 - 2/3 gallon).
A side note on thyroid problems; If you are suspecting that your thyroid are causing you problems you MUST go to a doctor and get a proper diagnose and treatment. Do never ever EVER think that changing the diet will be enough. Thyroid problems are deadly, and the treatments are often cheap and comfortable. Still, since I have an underfunctioning thyroid myself, I can't help but smile when I read that chocolate and saturated fat stimulates the thyroid. Turnip fried in real butter, mmmmmmm...
The turnip bulb is useful raw, in stews and casseroles and fried as an dish of its own. It gets wooden if it gets to big, so make sure to harvest before it's bigger than 10cm / 4" across. This should not be a big problem for an indoor gardener - I plan to harvest my first roots when they are as big as radishes. The leaves could be eaten fresh as salad, they are said to resemble ruccola in taste. In cooking they are used as - you guessed it - spinach.