Add some fresh walnut kernels to your salads (proportion to
taste). This add a crunchy freshness and contrasting taste to your fresh
greens.
Alternatively, add a small proportion of walnut oil to your
salad dressing. Use one part Balsamic or wine vinegar with four parts of a
good but unflavoured oil such as canola or sunflower oil, plus one part walnut
oil. Mix vigorously immediately prior to sprinkling over your salad and
tossing it to coat with the oil/vinegar mixture.
According to individual tastes (and to some extent the brand
of vinegar), these proportions may need to be varied but this will be a good
starting point.