Preheat the oven to 400°F. Add the Roma tomatoes, whole cherry tomatoes, bell peppers, onions, and garlic to a large rimmed baking sheet. Drizzle with olive oil and sprinkle with Italian seasoning, salt, and black pepper. Toss until everything is evenly coated, then spread the vegetables into an even layer. Roast for 40-45 minutes, or until the tomatoes are very soft and beginning to burst and the vegetables are tender and lightly caramelized around the edges.
Transfer the roasted vegetables and all of the juices from the baking sheet to a large pot. Add 2 cups of vegetable broth and blend with an immersion blender until completely smooth. Alternatively, carefully blend the vegetables and broth in a high-powered blender, then transfer the soup to a pot.
Place the soup over medium-low heat. Add additional vegetable broth, about 1/2 cup at a time, until the soup reaches your desired consistency.
Stir in the heavy cream and freshly grated Parmesan. Cook for 2-3 minutes, stirring occasionally, until the Parmesan has melted and the soup is hot and creamy. Do not bring the soup to a hard boil after adding the cream.
Taste and adjust the salt and pepper as needed. Ladle into bowls and serve topped with freshly shaved Parmesan and freshly cracked black pepper.
