How to Make It
Preheat the oven to 500°. Trim the radishes and wash the greens; pat dry.
In a large ovenproof skillet, heat the oil until shimmering. Add the radishes, season with salt and pepper and cook over high heat, stirring occasionally, until lightly browned in spots, about 2 minutes. Transfer the skillet to the oven and roast the radishes for 15 minutes, until crisp-tender.
Return the skillet to the burner and stir in the butter to coat the radishes. Add the radish greens and cook over moderate heat until they are wilted, about 2 minutes. Add the lemon juice and season with salt. Serve the radishes right away.