3. Step
Carefully transfer the tomatoes, onions and garlic to a blender. Add sugar to taste, thyme and the remaining 1/2 teaspoon salt and 1/4 teaspoon pepper. Blend, scraping down the sides as necessary, until very smooth, 1 to 2 minutes. (Use caution when pureeing hot liquids.) Garnish with more fresh thyme, if desired.