Spread bean dip on round place (12 to 14 inches in diameter). Remove seeds from avocados; place in food processor or blender with lemon juice, salt and pepper. Spread avocado mix over beans. Next, combine sour cream, mayonnaise and taco seasoning (you can vary spiciness with amount of seasoning used). Spread over avocado layer. Make a layer with green onions, then chopped black olives, then shredded cheddar cheese and tomatoes. Serve with tortilla chips.