Add oil to a wide skillet over medium-high heat. Add the green beans and ¼ teaspoon of salt.
Cook for about 5 minutes until lightly blistered, tossing the beans around the pan so they cook evenly.
Pour in water (or stock). Cover the skillet (or use foil if needed) and cook for 2 minutes.
Uncover, reduce heat to medium-low, and cook until the remaining liquid evaporates.
Stir in the butter, garlic, lemon zest, and pepper. Cook for another minute, stirring the garlic. Serve!