Bring a large pot of salted water to boil. Set a large bowl of ice water nearby. Add green beans into boiling water and blanch for 2 minutes. Drain and immediately put them in the ice water to stop the cooking process. Drain them once cooled off.
Melt 1 tablespoon butter in a skillet over medium high heat and add in slivered almonds. Sauté for 3-4 minutes, or until golden brown, stirring occasionally. Plate them out.
In the same skillet, add in 2 more tablespoons of butter and sauté sliced shallots and garlic for 5-6 minutes, until they start turning brown. Add in green beans and cook for a minute, or until they warm back up again.
Stir in lemon juice and season green beans with salt and pepper to taste.
Transfer the beans to serving platter. Top with toasted almond slivers and fresh lemon zest. Serve immediately
