Start by heating olive oil or butter in your stockpot over medium heat. Add the diced onions and minced garlic, stirring often until soft and fragrant—this should take about 3 minutes. This aromatic base sets the stage for the rest of the flavors to shine.
Now, toss in your sliced mushrooms. Cook them for around 5 minutes, until they soften and release their juices. Sprinkle in thyme, smoked paprika (if using), salt, and pepper. This step boosts the earthy flavor of the mushrooms and makes the kitchen smell amazing.
Next, stir in the chopped carrots and celery, then pour in the chicken broth. Turn up the heat and bring everything to a gentle boil. Once it starts bubbling, reduce the heat and let it simmer for about 10 minutes. This softens the veggies and infuses the broth with more depth.
Gently stir in the shredded rotisserie chicken, followed by the heavy cream. Let the soup simmer for another 5–10 minutes until everything is heated through. For a thicker, creamier texture, I sometimes blend about a third of the soup using an immersion blender.
Give your soup a taste and adjust the salt and pepper if needed. If you're feeling fancy, sprinkle chopped fresh parsley on top before serving for a pop of green and a fresh finish.