Tear up the lettuce if the leaves are large and place into a salad bowl
Cut the apple in thin slices. Then cut the thin slices into match stick lengths. Add to the bowl.
Cut the grapes lenthways. Remove pips if there are any. Add to the bowl.
Cut the celery into thin slices and add to the bowl.
Chop the walnuts up with a knife or crush in your hands. Add to a dry pan on a relatively high heat on the hob for about 5 to 10 minutes, shaking the pan regularly to avoid the walnuts burning. Remove from the heat once they start to roast and add to the bowl.
For the dressing, add all of the dressing ingredients into a small jar. Put the lid on and give the jar a good shake.
Pour the dressing over the salad. Toss the salad well to mix in the dressing, and serve.