Bring a large pot of salted water to a boil. Prepare a large bowl filled with ice and water on the side. Add the trimmed green beans to the boiling water and cook for 3 to 5 minutes until they are tender but still have a slight snap. Immediately drain the beans and plunge them into the ice water to stop the cooking process. Once cooled, drain them again and pat them dry with a towel.
In a large skillet over medium heat, add the sliced almonds in a single layer. Cook, stirring frequently, for 2 to 4 minutes until they are golden brown and smell nutty. Watch them closely as they can burn quickly. Once toasted, remove the almonds from the skillet and set them aside on a plate.
In the same skillet used for the almonds, melt the butter over medium heat. Once the butter is bubbling, add the minced garlic. Sauté the garlic for about 30 to 60 seconds until it is fragrant and soft, making sure not to let it turn brown or bitter.
Add the blanched and dried green beans to the skillet with the garlic butter. Toss the beans frequently for 2 to 3 minutes to ensure they are heated through and well-coated. Remove the skillet from the heat and stir in the toasted almonds, lemon juice, salt, and pepper. Toss one last time and transfer to a serving platter.