Here in Central NM, rainbow chard grows almost year-round; growth slows only during the coldest winters…and sometimes it gets a little nibbled on by grasshoppers at summer’s peak (but we’re ususally distracted by calabacitas, cucumber salads, and other summer delights).
The leaves are mild in flavor and can be used in all of the same ways you might cook spinach. Try it in creamy cheesy dips (or dairy-free with tahini). Greens love eggs: quiche, frittatas, scrambled, or crack some eggs directly into a pan of sauteed greens and let them poach. And then there are pasta dishes, soups, stews, stir-fries, casseroles, enchiladas, pizza, and more. Large leaves can be briefly blanched (30 seconds, tops) to soften them and stuffed, similar to grape leaf dolmas or cabbage rolls.
The stems are sweet and earthy, so don’t toss them. How many recipes begin with the instructions to soften a diced onion and other seasonings in a pan? This is the time to add your diced chard stems as well.
A note on oxalate/oxalic acid: our bodies naturally create oxalate when our guts break down vitamin C, but too much oxalate can be problematic for some people. You can reduce the oxalate content found in chard and other greens by blanching them for 2 minutes in boiling water. This is because oxalate is water-soluble; an NIH study found that blanching greens in this way reduces oxalate content by up to 90%. Furthermore, the National Kidney Foundation advises to eat oxalate-rich foods with calcium-rich foods such as dairy products or bone broth because oxalate binds to calcium and is thereby flushed from our systems. (Disclaimer: we’re farmers, not doctors, so none of the above constitutes medical advice. Point being, greens are nutritious and proper cooking makes food safer to eat.)