Position a rack in the center of the oven and heat the oven to 475°F. Line two heavy-duty rimmed baking sheets with parchment.
In a medium bowl, toss the asparagus with 3 Tbs. of the olive oil to coat generously, the salt, and a few grinds of pepper.Turn the asparagus out onto the baking sheets and arrange the spears so that they are evenly spaced (ideally at least 1/2 inch apart from each other).
Roast the asparagus for 5 minutes, then flip with a spatula or tongs. Continue to roast until the asparagus are tender and a bit shriveled, 5 to 8 minutes more.
While the asparagus finishes roasting, combine the remaining olive oil and the garlic in a small saucepan. Set over medium-low heat and cook until the smaller pieces of garlic turn light golden-brown, about 3 minutes. Stir in the coriander and cook for about 20 seconds. Immediately remove from the heat and transfer to a small heatproof bowl to prevent overcooking.
Remove the asparagus from the oven, and sprinkle with the lemon juice. Season to taste with salt and pepper, and arrange on a serving platter. Spoon the toasted garlic oil over the asparagus.