Place chopped carrots on a sheet pan. Drizzle with olive oil and season with salt and pepper. Toss to coat. Roast for 45 minutes, or until tender and golden.
Simmer 4 cups of chicken broth in a saucepan.
Pop garlic out of the skins and add to the sauce pan, along with the cooked carrots. Simmer for 15 minutes. Then add basil.
Puree in batches until smooth, adding half n half a little at a time. Serve warm.