In a large bowl, combine the cleaned radishes with olive oil, minced garlic, rosemary, thyme, salt, and pepper. Toss well to ensure the radishes are evenly coated.
Spread the seasoned radishes onto a baking sheet in a single layer for even roasting.
Roast in the preheated oven for about 25-30 minutes, or until they are tender and golden brown, stirring halfway through the cooking time.
Once roasted, remove from the oven and immediately sprinkle with lemon zest for a fresh burst of flavor.
Adjust seasoning to taste, adding more salt and pepper if necessary. Serve warm.