Spread the refried beans on the bottom of your serving dish

In a medium bowl, mash the avocados and mix in the salt, lemon juice, horseradish, and 1 cup of sour cream

Spread the avocado mixture on top of the beans

In another bowl, mix the remaining cup of sour cream, mayonnaise, and taco seasoning

Spread that on top of the avocado mixture

To that, add a layer of green onions, tomatoes, and olives

Finally, top it all off with the shredded cheese