01 - Preheat the oven to 425°F. Line a baking sheet with parchment paper.
02 - In a large bowl, toss the halved radishes with olive oil, salt, and pepper until evenly coated.
03 - Spread the radishes cut-side down on the prepared baking sheet in a single layer.
04 - Roast for 20–25 minutes, stirring once halfway through, until the radishes are golden and tender.
05 - While the radishes are roasting, melt the butter in a small skillet over low heat. Add the minced garlic and thyme; cook for 1–2 minutes until fragrant but not browned. Remove from heat.
06 - Once the radishes are done, transfer them to a serving bowl. Pour the garlic-thyme butter over and toss gently to coat.
07 - Garnish with additional fresh thyme and flaky sea salt if desired. Serve warm.