1 pound small radishes, trimmed of leaves and rootlets;
2 tablespoons butter;
1⁄2 teaspoon kosher salt;
1⁄4 teaspoon ground black pepper;
2 teaspoons chopped fresh thyme.
Preheat the oven to 475 F. Heat the oil over high heat in a large, heavy skillet (preferably cast-iron) until shimmering hot. Add the radishes and stir or gently shake the skillet to coat the vegetables in the hot oil. Cook, stirring or shaking the skillet occasionally, until the radishes are lightly browned in spots, about 4 minutes.
Transfer the skillet to the oven and roast until the radishes are barely tender, 10 to 15 minutes. Gently shake the skillet or stir the radishes every 5 minutes so that the vegetables do not scorch on the bottom.
Add the butter, salt, and pepper and stir to coat. Sprinkle with thyme and serve warm.
What else works? You can replace half of the radishes with whole baby turnips that are about the same size.