Cook bacon in a large skillet until crisp. Drain and set aside. Pour all but 1 Tbsp. bacon drippings from pan. Add oil and onion and cook over medium heat until softened. Remove from heat, add chicken broth, salt and butter.
Bring a pot of salted water to a boil. Add fettuccine. Add eggs in their shells to pasta pot and cook until pasta is al dente. Reserve 1 cup pasta cooking water and drain pasta and eggs in a colander together.
Bring sauce in skillet to a simmer. Add pasta and cook, stirring until heated through. Transfer pasta to a large bowl, add 1/2 to 1 cup cooking water and 1/4 cup Parmesan cheese and toss well. Peel eggs and chop. Sprinkle egg, crumbled bacon and chives on pasta and toss. Season with pepper and toss again. Sprinkle remaining 1/4 cup cheese over individual servings.