Preheat the oven to 190°C/375°F
Slice the peppers in half lengthwise, remove the seeds and stem, and place under the broiler skin side up.
Roast until the skin turns black , then transfer into an airtight container and place in the refrigerator for five minutes to loosen the roasted skin.
Use your fingers to rub off the black skin and set aside.
Place the tomato quarters and diced onion in a large roasting tin, season with salt and pepper, add olive oil, cider vinegar and muscovado sugar, and toss to combine. Put the garlic bulb halves in the roasting tin as well.
Roast in the oven for 40 mins.
Put the tomatoes with their juices in the blender, squeeze over the roasted garlic, add the roasted bell peppers and fresh basil, and process to obtain a creamy texture.
Distribute evenly into the serving plates, top with toasted seeds and basil pesto, add a drizzle of extra virgin olive oil, and serve warm, right away.