In a heavy skillet, melt butter over medium heat. Add onions, sugar, and 11/2 teaspoons salt. Sauté for 25 minutes or until onions begin to brown and caramelize. Place in a large mixing bowl, and let cool.

Meanwhile, place spinach in a colander, and press to drain liquid. Squeeze drained spinach tightly in small handfuls until almost dry. Add to onions. Add artichokes and water chestnuts to vegetable mixture. Set aside.

In the work bowl of a food processor, combine cream cheese, sour cream, mayonnaise, cream, garlic, remaining 1/2 teaspoon salt, pepper, lemon pepper, red pepper flakes, hot sauce, and lemon juice. Pulse several times until mixture is blended together. Add Parmesan, and pulse only a couple of times. (Note: Mixture should have a coarse texture.) Fold into vegetable mixture, and mix thoroughly. Serve at room temperature, or heat in a 350° oven until it bubbles and is slightly browned on top. Serve with bagel chips or pita chips.