Green Beans in Lemon Butter

1 tablespoon coarse salt, plus more for seasoning
1 pint green beans, stem ends trimmed
2 tablespoons unsalted butter, cut into small pieces
1 tablespoon finely grated lemon zest (about 1 lemon)
Freshly ground pepper

Fill a medium (3-quart) saucepan three-quarters full of cold water. Set over high heat, and bring to a boil. Add salt and beans. Cook until water returns to a boil and beans are tender, 4 to 5 minutes. Remove from heat, and drain.

Immediately return beans to saucepan. Add butter and zest. Toss and season with salt and pepper. Transfer to a serving bowl; serve warm.