Wash the radishes and slice them down the center. Leave the leaves on as they’re quite delicious when roasted. Arrange them on a rimmed baking sheet and drizzle with the olive oil and salt and pepper. Roast for 10 minutes then flip the radishes and roast for another 10 minutes, or until they begin to brown.
Arrange them on a platter and drizzle with the balsamic vinegar.