Preheat oven to 400 degrees F. In a bowl, combine the radishes and olive oil. Spread the radishes out onto a large edged baking sheet, or baking dish. Sprinkle with the salt and pepper.

Roast for 20 minutes, tossing the radishes about half way through. At 20 minutes toss again and add the garlic, shallot and oregano. Cook for an additional 10 minutes, or until they are golden brown and cooked through.