Wash and trim the spinach; pat dry with paper towels.
I usually pre-soak my walnuts so that they are ready to use for recipes. Just place them in a bowl and cover them with water. You can do this the night before you make them and drain the water when you are ready to use them. Chop the walnuts.
Peel the mandarin orange and separate the pieces.
Put the spinach in a salad bowl.
In another bowl combine the lemon juice, oil, stevia, and Tamari or Braggs.
Peel the avocado and dice it.
Mix in the diced avocado.
Toss the spinach salad with the avocado and salad dressing.
Add the walnuts and the mandarin orange and lightly toss the spinach salad again.
Serve this tasty spinach salad with walnuts immediately.