Gather and prep all of your ingredients.

Add the salmon, lemon juice, zest, and dill to a bowl. Mix together so that the lemon and dill coat the salmon, and allow it to marinate while making the soup base.

In a pan, heat the butter over medium heat. Once bubbling, add the red onion, celery, and garlic. Cook until fragrant, stirring often to prevent the garlic from burning.

Add in the chicken broth to deglaze the pan, scraping any bits off the pan's bottom. Add in the tomato paste and bring to a simmer.

If desired, blend some broth and cream cheese together, then return the cream cheese mixture to the soup base. Add in the cream and stir together.

Finally, add the salmon and capers and bring the soup to a simmer.

Serve immediately with some added dill and red onion sprinkled over the top. Enjoy!