Dice the carrots and celery into small cubes. Next, mince the green onions.
Preheat a soup pot or Dutch oven with a bit of oil. Add in the veggies and cook them until they soften. Add flour and red pepper flakes to the mixture, stirring to combine. Cook the flour for a couple of minutes to remove the raw flavor.
Add the water and chicken broth concentrate. Bring to a boil.
Dice the potatoes and smoked salmon into small cubes.
Add the smoked salmon and potatoes to the soup pot.
Add the heavy whipping cream to the soup. Bring it to a boil and immediately remove it from heat. Season with salt to taste.