Wash the jicama thoroughly, cut it in half lengthwise from the root to the stem.
Then peel off the brown skin and set the peeled jicama aside. I fine it easiest to use a sharp knife to peel the jicama but a vegetable peeler also works well.
Wash, and cut the apples into four pieces and remove the seeds. Set the prepared jicama and apples aside while you set up your food processor or mandoline.
Place the shredding attachment in your food processor. Shred the apple, then the jicama and then the parsley.
Remove the shredded jicama and apple and transfer it into a large mixing bowl.
Add the chopped parsley, salt and pepper to the bowl and mix all ingredients until well combined.
Next, add the mayonnaise and crema (or creme fraiche) and stir gently until well combined. You want the jicama and apple to be coated evenly.
Taste and adjust seasoning if necessary. Serve immediately.