In a large pot, bring 2 qt of water to a rolling boil. Add 1 tbsp coarse salt to the boiling water (this seasons the beans and helps preserve their bright green color).

Blanch

Carefully add the trimmed green beans to the boiling salted water. Cook until they are bright green and just tender-crisp, about 3 to 4 minutes depending on thickness. Test by tasting one—should have a slight bite but not be floppy.

Ice bath

While the beans cook, fill a large bowl with about 4 cups of cold water and ice cubes. Using a slotted spoon or a strainer, immediately transfer the blanched beans to the ice bath to stop cooking. Let sit 2 to 3 minutes until thoroughly chilled.

Drain

Drain the beans in a colander and gently pat dry with a clean kitchen towel or paper towels. Set aside.

Seasoning & Finish

Toast almonds (optional)

If using sliced almonds, warm a small dry skillet over medium heat. Add 2 tbsp sliced almonds and toast, stirring constantly, until fragrant and light golden, about 2 to 3 minutes. Transfer to a plate to stop cooking.

Sauté garlic

In a large skillet over medium heat, melt 2 tbsp unsalted butter with 1 tsp extra-virgin olive oil (the oil helps prevent the butter from browning too quickly). Add 2 minced garlic cloves and sauté just until fragrant, about 20 to 30 seconds—do not let it brown.

Finish green beans

Add the drained green beans to the skillet and toss to coat in the butter and garlic. Sauté for 2 to 3 minutes until heated through and lightly coated. Add 1 tsp lemon zest and 1 tsp fresh lemon juice, then season with 1 tsp kosher salt and 1 tsp freshly ground black pepper. Taste and adjust seasoning as desired.

Plate and garnish

Transfer green beans to a serving dish. Sprinkle the toasted sliced almonds over the top if using. Serve immediately.