Preheat oven to 430 F / 220 C. Place both types of tomatoes, onion, red bell pepper and garlic cloves, on a baking tray. Drizzle with 2 tablespoons of olive oil and season with salt and pepper. Toss the vegetables so that they are coated evenly.

Roast for about 25-30 minutes until the vegetables are soft and slightly charred.

While the vegetables are roasting, heat two tablespoons of olive oil in a large pot and fry the chopped potato until golden brown and cooked through.

Add the tomato paste and stock and cover until it comes to a boil.

Now add the roasted vegetables and cook for another 10 minutes on medium high heat.

Add the basil pesto and blend the soup until smooth. I used a hand blender to blend the soup, but you may use a blender as well.

Add the parmesan cheese if using, and stir it through until its melted.

Serve immediately with garlic bread or a side of salad.