In a bowl combine the chopped shallot, crème fraiche, and lemon juice, and mix to incorporate.
Chill and marinate for 30 minutes or longer.
Optional: add the cleaned chopped lettuce to the top of the radish mixture as a time saver. When ready to serve, toss the salad with salt and pepper.
Garnish the top of the salad with shaved apple and the chopped green onion.