Tart Granny Smith apples infuse this simple salad with classic fall flavor.
Heat broiler with rack 8 inches from heat. In a large bowl, whisk together oil, vinegar, and mustard; season. Add apples and toss to coat. Transfer to baking sheet and broil until browned at edges and softened, 5 to 8 minutes. Toss lettuce with apples and any juices. Sprinkle with chives.
