Sauté the Vegetables: In a large pot, heat the butter over medium heat. Add the diced onions, carrots, and celery, and sauté for about 5-7 minutes, or until they’re soft and aromatic. Stir in the garlic and thyme, and cook for another minute.
Add the Broth and Rice: Pour in the chicken broth and bring to a simmer. Once it’s simmering, add the rice, and cook according to the package instructions. Typically, white rice will take about 15 minutes, while brown rice may take a little longer (check the rice package for specific times).
Add the Chicken and Veggies: When the rice is just about done, add the leftover chicken and frozen peas (or any other veggies you’re using). Stir well and let everything cook together for another 5 minutes, allowing the chicken to heat through and the peas to soften.
Create the Creamy Base: Once everything is nice and hot, reduce the heat to low and slowly pour in the heavy cream. Stir to combine, and let the soup simmer for a few more minutes until it thickens slightly. If you want a thicker soup, you can mash a small portion of the rice or veggies with a spoon to release more starch into the broth.
Season & Serve: Taste the soup and adjust the seasoning with salt and pepper. Ladle the soup into bowls, and garnish with freshly chopped parsley or a sprinkle of grated Parmesan for an added touch of richness.