Creamy Roasted Cauliflower Soup

Ingredients

• 1 2-lb. head cauliflower, cut into florets (6 cups)
• 2 medium russet potatoes, peeled and cubed (2 cups)
• 1 cup chopped sweet onion
• 4 cloves garlic
• 3 to 4 tablespoons white wine vinegar
• 4 cups low-sodium vegetable broth
• ½ teaspoon freshly grated nutmeg
• ¼ teaspoon cayenne pepper
• Chopped fresh herbs, such as parsley, thyme, or basil
• Freshly ground black pepper, to taste