Place 6 cups of water and 2 tablespoons salt in a large pot over medium-high heat. Cover and bring it to a boil.

Meanwhile, fill a large bowl with ice and water. Line a sheet pan with a few sheets of paper towel. Set them aside.

Carefully add the green beans into the boiling water. Cook until crisp and tender, about 5 minutes.

Using a slotted spoon or a spider strainer, transfer the green beans into the ice water. Let them cool to room temperature completely for about 5 minutes. Drain and then transfer onto the sheet pan lined with paper towels. Dry as much as you can.

Melt the butter in a large skillet (10 or 12 inch) over medium heat. Add the garlic and cook, stirring constantly, for about 30 seconds.

Add in the green beans and gently stir to coat them with the butter and garlic mixture. Sautee, turning often, for 2-3 minutes or until green beans are softened but still tender.

If preferred, toss in the lemon zest at the last minute. Transfer the beans to a plate and serve.