Balsamic Roasted Asparagus

1 pound asparagus, trimmed by snapping the thicker ends off where they break naturally (about 10 to 12 ounces after trimming)
½ teaspoon extra virgin olive oil
2 teaspoons balsamic vinegar, divided
Sea salt and fresh ground pepper

Please note the thickness of asparagus spears varies widely.

Preheat the oven to 425°.
In a large bowl, toss the spears in the oil and 1 teaspoon of the vinegar. Season with salt and pepper. Let the seasoned asparagus sit for 10 minutes.
Lay the spears in a single layer on a medium nonstick baking sheet. Bake them for 4 minutes, flip them, and continue baking until the spears are crisp-tender, 3 to 6 minutes depending on thickness. Drizzle the remaining vinegar over the spears and toss well to coat. Season with salt and pepper to taste. Serve immediately.