Mashed Rutabaga with Onions

1 rutabaga, diced (about 4 to 6 cups diced)
1 cup chopped onion
2 tablespoons olive oil
1/2 teaspoon salt, or to taste
1/4 teaspoon ground black pepper

Cook rutabaga and onion in a small amount of boiling salted water until tender. Drain and mash; add olive oil, salt, and pepper. Mash rutabaga and onions well.

Adapted from: About.com: Southern Food [archive.org]