Bring 2-3 quarts of well-salted water to boil. Add orzo and cook until nearly tender, about 7 minutes, stirring occasionally. Drain, return to pan, drizzle with 1 tablespoon of olive oil and season with ½ teaspoon each salt and pepper, along with 1/8 teaspoon crushed red pepper. Stir.
While waiting for the water to boil, heat a large, deep skillet (12-inch) over medium heat with the other two tablespoons of olive oil. When hot, add the turnip, rutabaga, onion, fennel, and red bell pepper. Season with a good pinch of salt and pepper and, stirring often, sauté until nearly soft, adding garlic for the last minute or two.
Add the cooked orzo to the turnip mixture; stir. Add the lemon juice and zest; taste for seasoning, adding salt, pepper, crushed red pepper, and more lemon zest and juice if you like. Drizzle with a bit more olive oil as needed. Stir in chives or fennel fronds, if using. Cover and set aside to keep warm while you cook the lamb chops.