Preheat the oven to 200°C (about 400°F).
Chop the tomatoes, red peppers, and onion and arrange them in a baking dish with the garlic.
Drizzle with olive oil and season with oregano, paprika, salt, black pepper, and optional chilli flakes.
Roast for 45–60 minutes, until the vegetables are tender and nicely roasted.
Transfer the roasted vegetables to a pot and squeeze in the softened roasted garlic.
Stir in the tomato purée and cook for 1–2 minutes.
Stir in the balsamic vinegar, then add the vegetable stock and simmer for 10 minutes.
Add the fresh basil and blend until completely smooth.
Stir through the double cream and adjust the seasoning.
If the tomatoes taste particularly acidic, add up to 1 tsp sugar as needed.
Serve hot, ideally with a crispy grilled cheese for dipping.
