Mix together the chicken, celery, onion, pecans and cucumber in a medium-sized bowl. Place all the remaining ingredients in a small bowl and stir until the curry powder is mixed through and the mixture becomes a mustardy yellow hue. Add the mayonnaise mixture by tablespoons to the chicken mixture. (The salad should not be too wet or too dry -- you may not need all of the mayonnaise mixture.) Adjust the seasonings, cover with plastic wrap, and chill for at least 1 hour. Serve chilled on a bed of lettuce or mounded in a hollowed-out pineapple half.