Cut the kernels of corn off the cob. Set aside. Reserve three of the cobs.

Heat oil and butter in a large saucepan and sauté onions and garlic until soft. Add corn kernels and carrots and sauté for 10 minutes until they are beginning to soften. Add water, bay leaves and rosemary. Break the three cobs in half and place into the water as well. Bring soup to a boil.

Lower heat and add milk. Season with salt and pepper and simmer on low heat for 35 to 45 minutes, until vegetables are soft. Stir occasionally.

Remove the corn cobs, bay leaves and rosemary and blend the soup with an immersion blender.