Adjust an oven rack to the middle position and preheat oven to 450 degrees. Line a rimmed baking sheet with parchment paper or foil for easy cleanup.
In a large bowl, add radishes, olive oil, garlic powder, dill weed, salt and pepper (I like at least 1/2 teaspoon salt and 1/4 teaspoon pepper; sometimes I do a little more).
Transfer to prepared baking sheet cut-side down in an even layer. Roast until radishes pieces are tender-crisp and browning around the edges, about 35 to 40 minutes. Season to taste with salt and freshly ground black pepper.
Radishes: While they are available year-round, the best radishes arrive in April. These smaller, milder radishes are a treat for spring, and you might be able to find some additional rare varieties to enjoy.
Yield: 3 cups, enough for 6 1/2-cup servings.
Storage: Store leftovers in the refrigerator for up to 4 days. Add extra roasted radishes to omelets, scrambled eggs, and your meal prep containers.
Make ahead: Chop the radishes up to 3 days in advance. Store covered in the refrigerator until you're ready to roast.