1Preheat oven to 400 degrees. Toss tomato halves and olive oil. Arrange in a single layer cut side up on a rimmed sheet pan. Wrap unpeeled garlic in a tightly sealed foil pouch. Place garlic on pan with tomatoes. Roast 1 hour, remove from oven and let cool 1/2 hour.
2Open garlic pouch and peel garlic (the peel will pull right off). Place tomatoes and garlic in food processor and pulse until coursely chopped.
3Add tomato mixture and chicken broth to a large sauce pan. If using dried basil add that now. Over medium heat, heat to boiling, reduce heat and let simmer 25 minutes.
4Add fresh basil and half&half, heat through about 5 minutes and serve.