• Apple.
  Choose a tart variety: The green variety Granny Smith is regularly used. For a red, you can use Pink Lady.
   
• Grapes.
  Your choice. Choose a seedless variety if possible (the crunchy, green, seedless variety is particularly good for this salad).
  
   
• Celery.
   
• Diced red onion.
   
• Roasted/toasted walnuts.
  You can also use pecan nuts (and/or).
   
• Fresh lemon juice.
   
• Mayonnaise.
   
• Thick (Greek) yoghurt.
   
• Sugar (to taste).
   
• Condiments.
   

2. Method
 

• Core the apple(s) and then dice them (or make thin slices as you prefer).
  Add the apple to a mixing bowl.
  Douse the pieces with some lemon juice to help deter browning (oxidation - the enzyme polyphenol oxidase and phenolic compounds released from broken apple cells react in the presence of oxygen to form melanin).
  You may choose to add some sugar to balance out the tartness of the apples.
   
• Slice one to two stalks of celery, and chop up some of the leaves.
  Add these to the mixing bowl.
   
• De-stalk the grapes (your choice of quantity) and add them whole or halved to the bowl.
   
• Dice the red onion and add to the bowl.
   
• Separately, mix mayonnaise and yoghurt (1 part to 1 part).
   
• Add the prepared dressing to the salad and mix well.
  
  Note: You may choose to extend the salad by adding some form of protein in it.
   
• Taste and adjust with condiments, sugar or lemon juice if necessary.
   
• Your Waldorf Salad is now ready.
   

ENJOY!