Preheat broiler with oven rack 6 inches from heat. Toss haricots verts with salt, pepper, and 2 tablespoons of the oil. Spread in an even layer on an aluminum foil-lined rimmed baking sheet. Broil until beans are blistered, about 6 minutes, stirring after 3 minutes.
Heat remaining 2 tablespoons oil in a small skillet over medium-high. Add shallots, and cook, stirring often, until golden brown, about 5 minutes. Transfer to a plate lined with paper towels to drain.
Place haricots verts in a serving bowl, and toss with zest and juice. Sprinkle with shallots and macadamia nuts.