Heat your oven to 200°C/Fan 180°C/Gas 6. Slice the tomatoes into 6 wedges each. Peel and cut the onion into thick wedges. Pop all the wedges into a roasting tin. Drop in the unpeeled garlic cloves and drizzle over 2 tbsp olive oil. Season with salt and pepper and toss to coat in the seasoned oil. Slide into the oven and roast for 20 mins.

After 20 mins, carefully pluck out the garlic cloves and set aside. Turn the tomatoes over. Slide back into the oven to roast for another 20 mins till sticky, soft and lightly charred.

While the tomatoes roast, pour 600ml water into a large pan, set on the hob and bring to a boil. When the tomatoes have 8 mins left, and the water is boiling, add the pasta to the pan with a pinch of salt. Simmer for 8 mins.

After 40 mins total, remove the tomatoes from the oven. Peel the roast garlic cloves and add them to the tomatoes. Using a hand-held blender, blitz the tomatoes till smooth, then add them to the pasta and cooking water. No blender? Use a potato masher to crush the tomatoes instead. Stir the tomatoes, pasta and water together, adding a little more water if the soup is too thick for you.

Taste the soup and add more salt or pepper if you think it needs it. Ladle the soup into warm bowls, drizzle over the basil oil and crack over some black pepper to serve.