I've recently discovered that the vegetable you call "chard" is the same one we call "silverbeet".
It is one of my favourite vegetables, both for growing and eating. I let mine go to seed and find the self-seeded ones grow back just as well as any I have planted, and supply me with new seedlings popping up all spring and summer.
They transplant very well, use little room, and can be eaten non-stop as long as you keep picking the outer leaves and leave 4 or 5 centre leaves to keep the plant growing.
For cooking I use both the leaves and the centre spine/stem. The new young leaves get added to salads. The bigger leaves I chop up, steam and use anywhere you would use spinach. The stems (lots of lovely colours) I chop into 1cm lengths and use in stews, stir fries, pie fillings, etc.
In the stews they add bulk, although as someone mentioned they don't hold their colour well. (If you add too many red stems to a green dish it can leach the colour and make everything look a bit grey. eeeww.)
In the stir-fries they add colour and textural interest. They hardly need to be cooked, so they retain their lovely crisp texture.
For storage I cut the stem from the leaf and freeze them in individual bags. The leaves I blanch, squeeze the water out, then freeze. Use anywhere you might use frozen spinach eg in a feta and spinach quiche or for eggs florentine.
The stems I cut up, blanch and freeze. Then I throw it into a soup, stew, dhal, etc. while still frozen.
ONE problem = sometimes you get that furry feeling on your teeth from eating the older leaves. I think it's caused by oxalic acid (?). There is a remedy but I can't remember it.
Maybe a pinch of baking soda or a tsp of vinegar in the cooking water?