Trim the asparagus by cutting off about 3 to 4 inches of the woody stem. Mince the garlic, and zest and juice the lemon.
Add 1 tablespoon of the oil to a cast iron skillet, and bring the heat to high. When the pan is hot, add the asparagus, salt, and pepper. Cook for 5 minutes, stirring occasionally.
Lower the heat to medium. Push the asparagus to the sides of the pan, and add the remaining oil in the center. Drop in the garlic, and stir for 2 minutes, making sure it doesn't burn.
Add the lemon zest, and lemon juice. Stir to distribute the lemon and garlic. Simmer for 1 to 2 minutes covered. Remove from the heat, and serve the asparagus.