Preheat the oven to 400 degrees F (200 degrees C).
Cut radish bulbs from leaves and wash well to remove excess dirt.
Slice the radish bulbs thin, about ¼” (or ½ cm) thick.
On a medium baking sheet add olive oil and slides radishes and toss to coat radishes completely in oil.
Sprinkle with salt, pepper, and red pepper flakes (optional).
Roast radishes for a total of 20-25 minutes, tossing every 5-10 minutes to brown all sides of radish slices.
Remove from oven and serve immediately for best flavor and texture.
Enjoy!