Step 1

Preheat oven to 170°C.

Step 2

Halve each tomato horizontally and place on a large baking tray with onion, garlic and thyme.

Step 3

Drizzle with the olive oil and season well with salt and pepper. Roast in the oven for 1 hour or until the tomatoes are soft and caramelised. Set aside to cool slightly.

Step 4

Remove and discard thyme, then blend tomatoes, onion and garlic or press through a fine sieve or food mill.

Step 5

Stir in the basil and season as desired.