Preheat the oven to 400 degrees F (200 degrees C).
Place the asparagus and shallots in a large bowl, and pour the olive oil and 2 tablespoons of the vinegar over them. Season with salt and pepper, and toss to coat evenly. Spread the asparagus spears out in a single layer on a baking sheet.
Bake for 20 minutes in the preheated oven, or until tender and bright green. Shake the pan about half way through to roll the spears over so they cook evenly. Remove from the oven, and drizzle the remaining vinegar over the asparagus. Toss lightly to coat, and serve immediately.