Lasagne with Chard, Ricotta & Walnuts

(recipe from the book Local Flavors used with permission of the author, Deborah Madison) Serves 4- 6. 1 cup freshly cracked walnuts Sea salt and freshly ground pepper 2 to 3 pounds chard 2 tablespoons olive oil, plus extra for the dish 3 large garlic cloves, minced...