Snap off and discard tough ends of asparagus.
Arrange asparagus evenly on a lightly greased 15- x 10-inch jelly-roll pan. Drizzle with olive oil, and sprinkle with salt and pepper; toss to coat.
Bake asparagus at 400° for 15 minutes or just until tender.
Melt butter in a large skillet over medium heat. Cook, stirring occasionally, 4 minutes or until butter is lightly browned. Remove from heat; stir in soy sauce and balsamic vinegar. Drizzle over asparagus, tossing to coat. Serve immediately.