Bring the broth and water to a boil in a medium saucepan. Add chicken to broth and simmer, covered, for 8 minutes. Turn the heat off and let chicken stand in the cooking liquid, covered, until cooked through, about 20 minutes. Remove the chicken from the broth and cool completely in the refrigerator. Cut into 1/4-inch dice. Toast the almonds in a small dry skillet over medium-high heat until fragrant and beginning to turn golden, 2 to 3 minutes.
In a large bowl, stir together the yogurt, mayonnaise, and curry powder. Fold in the chicken, grapes and cilantro and season, to taste, with salt and pepper.
In a large bowl, toss the greens with the oil, lemon juice and salt and pepper, to taste. Arrange the greens on 4 individual plates, top with a scoop of the chicken salad and sprinkle with the almonds.