Some folks I write about live in a series of mutually-supporting, mostly self-sustaining agricultural stations/colonies on the edge of a desert, and are attempting to turn said desert greener.
Unfortunately, while they have everything from iceplant to genetically-engineered grass with interconnecting root systems on hand to keep the sand from lifting off and blowing away, they still need something edible to plant in order to increase their self-sufficiency in the long run.
More unfortunately, climate change is involved with this world, and it's gone rampant. The temperature where they live is ~45°C/~113°F - during the coldest parts of winter. It doesn't get colder for them; their version of "winter" is due to their planet being on an elliptic orbit, rather than due to axial tilt, which it basically has none of. Growing season is 1/4 of the Earth-year-length year, and that's pushing it: they plant their crops as soon as the temperature gets below roughly ~50°C/~122°F (long story, religious reasons based off of one of the last working terraforming robots) and hope it isn't too late.
As such, this colony needs some kind of edible plants - preferably as many separate species of them as possible, in order to provide backups in case one goes extinct, to preserve genetic diversity (i.e. one random disease can't wipe out the entire crop), and to keep people sane by providing them with multiple food sources. Additionally, said plants must be as resistant to high temperatures as possible; while I recognize that surviving 122 degrees Fahrenheit is a tall order, anything that can get even remotely close to that is good in my books.
Precipitation and soil are not a concern; the substrate produced by the already-planted soil remediation plants is sufficient for pretty much anything to grow in, and they have a vast network of moisture farms that can provide them with as much water as is necessary. Moreover, it's fine if said edible plants require processing before being eaten, since, on top of that, they possess a high degree of automation; this also means that, say, selectively-bred giant pumpkins that weigh more than a metric ton each are an option here.
However, they have to grow as well as possible in such crazy conditions - not strugglingly, not dying before they produce any edible matter, but well enough to actually be usable as a food source. Moreover, hydroponics aren't really an option at the scales they're working at, and they're trying to build an ecosystem, not a farm. Perhaps initial crop specimens can be selectively bred, but eventually they're going to need to start planting outside the greenhouse, so to speak.
If this is just plain impossible, answer with that - hence the "reality-check" tag.