Preheat oven to 400 degrees. Place radishes on a baking sheet, drizzle with olive oil and sprinkle with salt and pepper. Roast 35-40 minutes, or until radishes are soft and tender (cooking time may vary based on how small or large radishes are).
Once radishes have cooled, combine in a blender: roasted radishes, beans, broth, and rosemary. Blend for 30-60 seconds or until pureed smooth. Taste and add a pinch of salt if desired.
Store in a sealed, airtight container in the refrigerator up to a week.