Prep. Preheat oven to 400 F. Toss ingredients together, making sure the halved radishes (3 pounds) are thoroughly coated in olive oil (1/4 cup). Spread radishes onto a rimmed baking sheet, placing the cut side down -- I do this on 2 baking sheets so the radishes aren't overcrowded.
Bake. Roast for 25 minutes. Flip radishes, and roast another 20 minutes on the other side. Radishes are done once they've browned to your liking. (I usually add another 10 minutes to this time, this will vary with how crowded the pan is and how brown you'd like them). Serve warm and enjoy!
Notes
Nutritional information is for 1 serving if you divide this recipe into 6 servings: