Put the aubergine in a lightly greased roasting dish and bake for about 30-45 minutes in a medium hot oven. When you can insert a skewer easily into the aubergine, it’s properly cooked through. Take it out of the oven and let it cool.
Meanwhile, cut the tomatoes in half, place them on another tray. Put the garlic cloves and chilli pepper between the tomatoes. Drizzle some olive oil on the top, dust with the oregano, then season with salt and pepper.
Bake for 25-30 minutes until the tomatoes are tender.
Transfer the tomatoes and their cooking juices to a blender. Pop the garlic flesh out of its skin, add the flesh to the tomatoes. Remove the skin of the chilli, deseed and add the flesh to the tomatoes.
Scoop out the flesh of the aubergine into the blender.
Whizz for a few seconds, then add your chosen herb. Season with salt and pepper, add a few squeezes of lemon juice and blend again until you get a textured sauce. Taste and adjust the seasoning and lemon juice.
Transfer the sauce into a serving dish or jar and keep chilled until needed.