Preheat the oven to 220C / 200C fan / gas 7
If using tinned corn, drain and pat dry. If using frozen, defrost and dry in the same way. Put the corn on a large lined roasting tray and drizzle with 1 tbsp oil. Place in the preheated oven and roast for 20-25 minutes until starting to char.
While the corn is roasting, take a large pan and place over a medium heat. Add the remaining oil and place the onion, chilli and red pepper in the pan and cook until the onion begins to soften, 6-8 minutes.
Stir in the garlic, smoked paprika and chipotle paste, if using and cook for a few minutes.
Reserve some of the roasted corn for garnish and then add the rest of the corn to the pan. Add the hot stock and the coconut milk and bring to the boil, lower the heat and simmer for 5-10 minutes.
Remove from the heat and ladle 1/2 soup into a blender and blitz until smooth. Then return this back to the pan and mix through.
Add the lime juice, season to taste.
Ladle into warm bowls and serve topped with the some of the reserved corn, lime zest, spring onions and coriander.