In a large heavy bottom pot over low heat, heat the olive oil. Add the garlic and sautee for a minute, then add the carrots and sautee about 3-4 minutes until starting to soften. I like to salt a bit at this stage, maybe about a ¼ teaspoon of salt.
Stir and add the cauliflower, and about 3 cups of water, just enough to cover the vegetables. I like a thick soup so err on the side of less water rather than more. Bring to a boil, then reduce heat, and, partly covered, simmer the pot until the vegetables are soft.
Stir in the white beans and remove from heat. In a blender or using an immersion blender, puree soup until smooth. Season with salt and pepper to taste.