Swiss Chard is one of my favorite green vegetables. I like the "Bright Lights" (aka "Rainbow") variety the best, as not only do the stems seem more tender & less fibrous to me than the white & ruby types, but the stems also retain most of those lovely colors after cooking.
My favorite way of preparing it is to bring a large pot of water to a boil. Separate the leaves from the stems, slice the stems into 1" pieces & boil for 5 minutes. Roughly chop the leaves & add them to the water as well for another 5 minutes. Drain well in a colander. Put a couple of dollops of extra-virgin olive oil in a large skillet & stir in a few cloves of chopped garlic for just a minute or so (DON'T let your garlice brown/burn). Add in your drained chard along with a couple of dashes of crushed red pepper flakes, a squeeze of lemon juice (or wine vinegar or dry white wine), & a small handful of dry bread crumbs to help bind in all those wonderful flavors. Makes an absolutely delicious accompaniment to Turkey or Chicken Piccata, or a Greek or Italian-style fish dish. Leftovers also make a wonderful filling for a stuffed meatloaf.