In a large bowl, mash the avocado with lemon juice, yogurt, and mayonnaise until mostly smooth (chunks are perfectly okay!).
Add chicken and red onion, stirring until thoroughly coated. Add salt and pepper to taste. The salad is best if it can sit in the refrigerator for a bit but is still delicious served immediately on top of a toasted English muffin, bread, or lettuce. Don't forget to add your favorite toppings!
Notes
This is a very adaptable recipe. A "throw in what you like or take out what you don't" type! Sometimes I'll added about 1 cup of shredded cheese or dice up pickles and throw those in. This sandwich is your oyster!
You can use all yogurt to make this salad very healthy, but I personally love the flavor a little mayo adds!