2 pounds carrots, peeled and diced
1 quart carrot juice
2 tablespoons butter
2 teaspoons brown sugar
1 sprig thyme
salt to taste (about a teaspoon) 

Sweat carrots with butter, brown sugar, and thyme in large pot until they begin to soften. Add carrot juice, and cover and simmer over low heat until very tender, about 20 minutes. Once carrots are tender, remove the lid and reduce the liquid until almost dry.

Remove spring of thyme. Purée the carrots and the reserved liquid in a blender on high speed until very smooth. Pass through a chinois and serve.