Preheat oven to 300°F. Fill a medium pot with water and season generously with 3 tbsp salt. Bring to a boil.
While you wait, trim the ends of 1 1/2 lbs green beans. Grate enough gruyère to fill 1 cup (if you haven't already!). And make 1 batch lemon-garlic vinaigrette. Set aside. Transfer 1/2 cup raw sliced almonds to a baking sheet and bake until light golden brown and toasted, about 10 minutes. Shake the pan and rotate half-way to ensure even browning.
While that bakes, add the trimmed green beans to the boiling water and turn off the heat. Let the beans cook for 3-4 minutes, or until bright green. While they cook, fill a medium bowl with cold water and 10 ice cubes. When the beans are cooked, but still have a slight crunch, transfer them to the ice bath. Let sit in the cold water for 1-2 minutes, then strain and place them back in the medium bowl.
Cover the beans in 1 batch lemon-garlic dressing and toss. Transfer the dressed beans to a serving dish and cover with grated gruyère and roasted almonds.
