Remove the tough ends of the asparagus and lightly peel the stalks with a vegetable peeler.
In a heavy skillet over medium-high heat, melt the butter and add the Mastiha powder and asparagus, shaking the pan slightly to ensure they are in a single layer. Increase the heat for 1-2 minutes and season with salt and pepper.
Lower the heat and cook the asparagus for 8-10 minutes, until lightly browned on all sides. Drizzle with a few drops of lemon, sprinkle with parsley, and serve.
