Legumes are interesting in that there are many crops that can be companion planted. Can they get to quantities that can sustain a family? I don’t know. But pole beans are known to grow better as a companion plant to corn than by themselves. There are many other types of legumes — the Mesquite tree here in my neck of the woods (lower Sonoran) is a nitrogen fixer, with some varieties producing bean like pods that can be harvested. (They require a mill to get the full use pf them).
My point is that there is a lot more options out there, and what is possible is a lot greater than people think.
As far as wheat goes, I have not heard much from permaculturists doing that. I hear more about cultivating amaranth and quinoa as nutritionally dense pseudo grains.
Generally, I also hear a lot more about winter squashes. That follows the design principle of “Catch and Store Energy”, with squashes being a very durable store of sunlight and nutrients. Speghetti squashes can be made into pasta-like noodles. Not so much with bread.
Cauliflower can be processed to make a kind of flour that can be used in a lot of baking. Again, I don’t know the yields that can sustain a family. Depending on where you are, they are a fall crop. (They are a winter crop for the lower Sonoran, zone 9b/10). Probably grown in succession so that they can be had for a while. Maybe the flour can be stored over winter.
There are also sunchokes. These are in the sunflower family, and are considered invasive. They are very hardy, and their tubers can be harvested during a time when few other plants can be harvested. Their flowers open late season, and also nourish pollinators at a time when they don’t have a whole lot of options. They will grow in poor, depleted soil, and will probably edge out other pioneer plants. So not bread for the winter, but a good source of calories nonetheless.
Maybe that will the challenge my wife presents to me: finding the a good set of crops that would allow her to bake.