In a 12x12 inch or larger dish, evenly spread the refried beans in a thin layer.
In a medium bowl, mix the avocado and lemon juice until almost smooth. A few avocado lumps are desirable. Spread the avocado mixture over the refried beans. In a medium bowl, blend the sour cream and taco seasoning; spread over the avocado mixture. Sprinkle the tomatoes in a layer over the sour cream mixture, followed by the olives and the green onions. Top the dip with a layer of cheese.