Begin by pouring 2 tablespoons of olive oil into a large pot and preheating it over medium heat. Allow the oil to shimmer, indicating it's ready, then add 1 medium diced onion and sauté for about 3 minutes until translucent. Follow this by incorporating 2 minced garlic cloves, stirring for another minute until fragrant and the aroma fills your kitchen.

Next, toss in 2 diced carrots and 2 diced celery stalks into the pot, stirring to combine. Sauté the mixture for 5 to 7 minutes until the vegetables soften and take on a lovely golden color.

Once the vegetables are perfectly tender, add 1 pound of shredded cooked chicken to the pot. Pour in 4 cups of low-sodium chicken broth, followed by 1 cup of frozen peas, 1 teaspoon of dried thyme, and 1 teaspoon of rosemary. Stir everything together and bring the mixture to a gentle simmer, allowing it to bubble softly for about 5 minutes.

In a separate bowl, whisk together 1/4 cup of all-purpose flour and 1 cup of heavy cream or milk until smooth. Gradually pour this mixture into the simmering soup while stirring continuously.

Continue to simmer the soup for 10 to 15 minutes, stirring occasionally. You’ll notice the soup thickening and becoming creamy during this time. Adjust the seasoning with salt and pepper to taste.

Once thickened to your liking, remove the pot from heat and let it sit for a few minutes.