1. Place pecans in a small skillet. Toast over medium heat, until they just begin to smell toasted and turn light brown. Shake skillet to toast evenly. As soon as nuts start to color, remove from heat and pour onto a plate to cool. Set aside.
2. Combine mayonnaise, vinegar, buttermilk, syrup, and curry powder in a jar witha tight-fitting lid. Shake vigorously until ingredients are well combined.
3. In a large bowl, combine chicken, toasted pecans, cranberries, scallions, salt, and pepper. Toss to mix, then pour dressing over salad to taste. (You might not need all of it to moisten the salad to your liking.) Store extra dressing in jar, refrigerated, for up to 3 days.
4. To serve, line a serving plate with the greens and mound the chicken salad in the middle. Serve at once, or refrigerate for up to 2 hours before serving.