Method
Bring a pot of water to a boil. Reduce to a gentle simmer, add the chicken and cover. Let it simmer until the chicken is cooked through, about 15 to 20 minutes. Remove the chicken from the pot and cut it into small cubes. Let it cool completely.
While the chicken cools, in a large mixing bowl, mash the avocado until only a few small chunks remain. Stir in the lemon juice, olive oil and salt.
Fold the red pepper, cucumber, green onion, mango and chicken into the avocado mixture until well combined. Season with additional salt or lemon juice if needed.
Divide spinach onto plates and top with chicken salad. Enjoy!