Drain artichoke hearts well and chop. Mix with mayonnaise, cheese, and garlic powder. Bake in oven proof casserole at 350°F for 25-30 minutes. Serve with crackers. Ingredients may be mixed ahead and baked later, but not frozen.
Juice lime into non-metallic dish. Cut open avocadoes, and using a large spoon, scoop flesh into the dish, discard seed. Toss with the lime juice, then coarsely mash. Dice tomato, then gently squeeze portions of the diced tomato in your hands to remove excess juices. Add tomato, cilantro, and green chiles to the avocado mixture and stir well. Add salt to taste.
Note: The type of avocado makes a big difference in the quality of this dish. The California Avocado Commission discusses the difference in taste. Hass avocadoes (they have a black pebbly skin) are fairly common and taste great. The most common one to avoid is the Bacon variety (smooth green skin, often seen in stores during winter).
Peel the oranges. Remove all pith, then slice as thinly as possible in food processor. Remove seeds, arrange in overlapping circles in the serving bowl. Slice the onions as thinly as possible and layer over. Then scatter on the olives (chop if large). Sprinkle with salt and cayenne, then the oil. Strew liberally with herbs—I prefer a mixture of parsley, mint, and chervil. Dill, lemon balm or whatever is fine, too. Be very generous with the herbs.