You order guacamole most anywhere in town and you know what to expect - a bowl of mashed avocado mixed with salt, lemon or lime, and one pepper or another. You order guacamole at Casita in Sherman Oaks - and you get a Las Vegas production. There's a large bowl of guac, mixed with onions. There are five salsas, ranging from a classic tomato and pepper salsa to one that looks and tastes like salad dressing.