Here is a simple salad with a complexity of favors that belies its ease to make.  It includes spicy arugula, subtly sweet and earthy beets, rich walnuts, and tangy Gorgonzola.  I love that it has such an interesting interplay of ingredients that just like being together. Beet, Arugula, and Gorgonzola salad (serves 2) 1 quart…