Salt & pepper Warm the olive oil over medium-low heat in a small, heavy saute pan. Add the rosemary & walnuts & saute for 5 minutes. Do not let either one brown. Sprinkle the walnut mixture with salt & pepper & stir into the cooking polenta about 10 minutes before it is completely cooked. Continue stirring & cooking until the polenta is ready to serve. Serve immediately or cool to make crostini.