Heat a large Dutch oven or soup pot over medium heat. Add the butter and oil and swirl the pan until the butter is melted. Add the onions, shallots, bell pepper, smoked paprika, sweet paprika, oregano and thyme and stir to combine.
Cook for 4-5 minutes, stirring occasionally until the veggies are soft and the onion is translucent. Add the garlic and cook for another minute, stirring frequently.
Add the broth, carrots, cauliflower rice, soy sauce, brown sugar, salt, pepper and bay leaves. Bring the mixture to a boil then reduce to a steady simmer and cook, uncovered, for 20-25 minutes or until the carrots are nice and tender.
While the soup is simmering, prepare the mushrooms and the chicken, (if using) (See preparations below.)
Remove the pot from the heat and discard the bay leaves. Using an immersion blender or a regular blender, puree the mixture until nice and smooth.
NOTE: If using a regular blender, be sure to allow the mixture to cool a bit before blending and vent the blender by removing the center cap. When blending, cover the opening in the blender top with a funnel, a clean kitchen towel or several thicknesses of paper toweling.
Add the sautéd mushrooms to the soup, place the soup over medium heat and bring to a simmer. Once the soup is simmering, add the prepared chicken and stir well to separate the pieces.
Cover the pot, turn off the heat and allow the soup to sit (undisturbed) for 10 minutes.
Uncover and add the heavy cream and fresh dill (or rosemary). Stir to combine then take a little taste and adjust the seasoning, if needed, with more salt and pepper.
Ladle into bowls and top with a spoonful of sour cream and a little extra dill (or rosemary) Serve and enjoy!