Add the carrots and celery and continue to cook over medium heat for around 10 minutes. The vegetables should be starting to get a little soft.
Add the tomatoes and stir to combine.
Add the stock and increase the heat to high. Bring to a boil.
Reduce the heat to a simmer and cover the pan.
Simmer, stirring occasionally, for around 30 minutes. The vegetables should be quite soft at this time - you should be able to crush them with the back of a fork.
Remove from heat and season to taste.
Allow to cool before you use an immersion blender or a regular blender to blend the soup until smooth.
For the croutons:
Pre-heat the broiler (grill) to medium-high.
Toast your bread, then sprinkle the cheese evenly over the top of each slice.
Place bread on a baking tray lined with parchment and place under broiler until the cheese is melted and bubbling.
Remove from heat and allow to cool slightly before cutting into croutons.
Serve on top of the soup.
Recipe by eat. live. travel. write. at https://www.eatlivetravelwrite.com/2016/06/fire-roasted-tomato-soup-with-grilled-cheese-croutons/