Trim the woody ends from the asparagus and rinse thoroughly under cold water. Pat dry with a towel.
Slice the garlic cloves as thinly as possible to maximize aroma and quick cooking, and set aside in a small bowl.
Heat a large skillet over medium-high heat until shimmering, then add the butter. Let it melt and bubble gently, releasing a nutty aroma.
Arrange the asparagus in a single layer in the hot skillet. Listen for a sizzle, and cook for about 3-4 minutes, turning occasionally with tongs, until the spears blister and turn a bright, vibrant green.
Add the sliced garlic to the skillet, stirring quickly so the garlic coats the asparagus evenly. Cook for an additional 1-2 minutes until fragrant and lightly golden, being careful not to burn.
Check the texture of the asparagus; it should be tender but still have some snap, with blistered tips. If you like softer spears, cook for another minute, but avoid overcooking to prevent limpness.
Squeeze fresh lemon juice over the asparagus, if using, then season generously with flaky sea salt and freshly cracked black pepper. Toss gently to distribute evenly.
Remove the skillet from heat and transfer the asparagus to a serving plate. Let sit for a minute to allow flavors to settle.
Finish with an extra sprinkle of flaky salt or a small pat of butter if desired, and serve immediately while hot and fragrant.
