Since folks always seem to be looking for new uses for tasty, super-nutritious kale (such as these great 15 Ways with Kale), let me throw out one of my favorite summer kale treats: kale pesto. Kale's a hearty green and very well suited to cold-weather cooking. But that doesn't mean you have to put it aside all summer. Try this simple substitution: take your favorite pesto recipe, and swap kale for basil or whatever green you typically use. With kale pesto, I usually sub sunflower seeds for pine nuts also—they're much cheaper and their flavor seems to suit earthy kale better.
A quick tip: Because kale leaves are considerably tougher than basil, it helps to blanch it first before blending with the other pesto ingredients. Just give the kale leaves a dip in boiling water (15 seconds or so, just enough to wilt them and bring out their greenest color). Then plunge them into an ice water bath to stop the cooking and set the color. This will tenderize them for puree, and also make the pesto a brilliant emerald green.
Use kale pesto any way you'd use basil pesto: stir it into pasta dishes, top bruschetta and pizzas, and so on. One of my favorite ways to use it is in grain salads, served cold or at room temperature. Cook a cup or so of your favorite whole grains (like farro, wheatberries, or millet), then dress them with olive oil, vinegar or lemon juice, and salt and pepper while still hot so they absorb the flavorings. Let the mixture cool (so it doesn't discolor the pesto), then stir in pesto to taste. Add chopped tomato, cuke, and onion, and finish with a little chopped parsley. Great for picnics or light but satisfying lunches.