Half the tomatoes, add chillis, sliced onion and the garlic with the thyme to a roasting tray drizzle with olive oil, season with salt and pepper, roast them for 35 mins at 180c
Meanwhile add the onions, garlic and celery to a pan with a pinch of salt and a splash of olive oil. Soften the veg until it just starts to brown a little then add the tomato purée
Cook out the purée for 2 mins then add the basil and stock simmer for 30 mins
Add the roasted goodies and stock mix to a blender, if it's still hot make sure the steam can escape
Pass through a sieve if desired and check for seasoning
Sandwich plenty of cheese in between two pieces of crusty bread buttered on the outside. Fry in a little olive oil pressing down to get an even finish and melt all that cheese
Serve the soup with a drizzle of olive oil, a few basil leaves and extra black pepper
