Preheat oven to 500. Wash radishes. Trim off radish greens and set aside. Halve radishes.
Heat olive oil in a skillet (oven-safe if available) on medium-high heat and add radishes. Season with salt and pepper and cook for two minutes. Transfer to greased baking sheet and place in oven (or place oven-safe skillet in oven) and roast for another 15 minutes.
Remove from oven and return to skillet (if using baking sheet). Add butter and radish greens. Season with salt and lemon juice. Cook on medium heat until greens are wilted.
