Preheat the skillet: Heat a cast iron skillet over medium-high heat until hot.
Cook the asparagus: Add olive oil and asparagus to the skillet. Cook for 3–4 minutes, turning occasionally until lightly charred and just tender.
Add garlic and lemon: Reduce heat to medium. Stir in minced garlic and cook for 30 seconds, just until fragrant. Add lemon zest and juice, and toss to coat.
Season and serve: Season with salt and black pepper. Serve immediately, straight from the skillet or transfer to a serving dish.