Preheat the oven to 200°C.
Place the tomatoes and onions on a roasting tray and drizzle with half the extra virgin olive oil. Season with salt and roast for 30 to 40 minutes, or until the tomatoes and onions are soft and starting to char.
When the tomatoes and onions are almost ready, make the soup base. Heat the remaining oil in a saucepan over medium heat. Cook the garlic, chilli and coriander each for 1 to 2 minutes or until fragrant, stirring all the time.
Add the chopped tomatoes and coconut milk, stir and simmer for 10 minutes.
Remove the saucepan from the heat and add in the roasted tomatoes and onions – including any pan juices. Stir and set aside to cool slightly as you cook the noodles.
Using an immersion blender*, puree the soup until smooth.
To serve, add a portion of noodles to each bowl of soup and squeeze over some lime.