Roasted Tomato and Lentil Soup

1.5kg roma tomatoes, halves lengthways
1 T balsamic vinegar
¼ C olive oil
Salt and pepper
1 brown onion, finely chopped
2 garlic cloves
2 T tomato paste
6 C chicken stock
1 ½ t brown sugar
400ml can brown lentils, drained, rinsed
2 T basil leaves, chopped
Preheat oven 220°C. Line 2 baking trays with baking paper, arrange tomatoes cut side up, drizzle with vinegar and 2 T oil and season. Roast 10 mins. Swap trays in oven, roast another 10 mins until tender. Process until smooth. Heat remaining oil in pan, cook onion and garlic 2-3 mins until soft. Add tomato paste 1 min. Add stock, sugar, roast tomatoes, cover and bring to boil. Reduce heat and simmer uncovered 15 mins. Stir in lentils and simmer 5 mins until heated through. Season. Serve with basil.