Instructions

1. Preheat oven to 450°F. Toss together cauliflower, onion, garlic, oil, Italian seasoning, salt, and pepper in a large bowl. Divide mixture between two foil-lined rimmed baking sheets. Roast 25 to 30 minutes or until browned and tender.
2. Meanwhile, melt butter in a Dutch oven over medium heat. Add flour, stirring constantly 1 minute. Gradually whisk in half-and-half and broth; bring to a simmer, and cook 3 to 5 minutes or until thickened, stirring.
3. Process roasted cauliflower and 2 cups of broth mixture in a food processor or high-power blender until smooth, scraping sides are needed. Or use an immersion blender.
4. Stir pureed cauliflower mixture into remaining broth mixture. Cook 2 minutes or until thoroughly heated. Stir in cheese until melted.
5. Swirl pesto into soup just before serving.