Prepare an ice bath. Bring a 4-quart pot of lightly salted water to a rolling boil. Add haricots verts, and blanch until vibrant green, about 5 minutes. Drain in a colander, and transfer to ice bath. Let stand until cool. Drain in colander, and thinly slice haricots verts on the bias.
Heat oil over medium-high heat in a large skillet. Add garlic, and cook until just golden, 1 minute. Add ginger and chile, and cook for 1 minute more. Add blanched haricots verts, and cook, tossing, until heated through. Season with salt. Add sesame seeds and lemon zest, and toss to combine.