Preheat your oven to 200°C (390°F). Place a rimmed baking sheet in the oven as it heats to ensure even roasting.
Trim the woody ends off the asparagus, about an inch from the bottom, and rinse the spears under cold water. Pat dry thoroughly to help them roast evenly.
In a small bowl, whisk together the olive oil and thinly sliced garlic, allowing the garlic to infuse in the oil for a few minutes.
Arrange the asparagus in a single layer on the hot baking sheet. Drizzle the garlic-infused oil evenly over the spears, turning them gently with tongs or spatula to coat all sides. Sprinkle generously with flaky sea salt.
Slide the baking sheet into the oven and roast for 12-15 minutes. During this time, the asparagus will turn vibrant green, and the garlic slices will deepen to a golden color and release a fragrant, smoky aroma.
Check the asparagus for doneness by piercing the thickest part with a skewer or fork; it should feel tender yet still have a slight snap. The tips may be blistered and slightly charred, adding flavor.
Remove the baking sheet from the oven. Squeeze fresh lemon juice over the roasted asparagus and sprinkle with freshly cracked black pepper if desired. Toss gently to combine and let rest for a minute to allow flavors to meld.
Arrange the asparagus on a serving plate, spooning any pan juices over the top. Serve immediately while the aroma is still vivid and the asparagus is hot and tender.
