To toast nuts: place nuts on a cold fry pan and turn the heat to medium. Stir or toss frequently. The nuts should become lightly browned and begin to smell fragrant when they are done. Remove them from the heat immediately and turn out of pan into the salad or a small bowl until you are ready to use them. You will need to keep a close eye on the nuts. It should only take about 5 minutes to toast them. They can burn very quickly once they are toasted.
If you do not have walnut, you can substitute sunflower seeds in the recipe. Toast them according to the instructions above.
Toasting is not completely necessary, but it does improve the flavor of the nuts.