Cook pasta according to package directions. Meanwhile, cook bacon in a large skillet until crisp; remove bacon, reserving 1 tbl. drippings in skillet. Coarsely crumble bacon, and set aside.
Cook green onions and mushrooms in drippings in skillet over medium heat 2 minutes. Drain pasta, and place in a serving bowl. Stir egg yolks into hot pasta immediately after draining it. Stir in bacon, green onions and mushrooms, cheese and pepper; toss. Serve immediately.