Preheat the oven to 425 degrees Fahrenheit.
Snap or cut off the tough bottom ends of the asparagus spears. You can snap them off by bending the spear near the end of the stalk, and the tough end will naturally snap off. This method works best for thinner spears. If you have very thick spears (like I did this time), just use a knife to cut off the bottom inch or so of the spears. That will help get rid of the stringy/woody pieces that can sometimes be at the bottom of the asparagus spears as they dry out.
Spread the spears on a large rimmed baking sheet. Drizzle generously with olive oil, then sprinkle with a large pinch of kosher salt and sprinkle all over with ground black pepper (don’t be shy with the seasoning!). Use your hands to toss to coat and spread the spears out evenly.
Place the baking sheet in the oven and roast for about 15 minutes (if you have thick spears). Less time will be needed for thin spears. You’ll know the asparagus is done when a fork easily pierces the thick part of the stalk and the tips are starting to get browned and crispy.