Here, radishes are cooked with kimchi that caramelizes as it cooks, resulting in an umami butter sauce. Slideshow: More Radishes Recipes
Preheat the oven to 450° F.
In a large cast-iron skillet, melt 2 tablespoons of the butter. Add the kimchi and cook over moderately high heat, stirring, until golden, about 5 minutes. Add the radishes and their greens, the remaining 2 tablespoons of butter, and season with salt and pepper; toss to evenly coat. Roast in the oven for 25 to 30 minutes, stirring occasionally, until the radishes are tender and golden. Stir in the lemon juice and serve warm.