01 - In a large pot or deep skillet, melt the butter over medium heat. Add the onions, carrots, and celery. Sauté for 4–5 minutes, stirring occasionally, until the vegetables begin to soften.
02 - Stir in the minced garlic and cook for 1 minute until fragrant, being careful not to let it brown.
03 - Sprinkle the flour over the softened vegetables and stir to coat everything evenly. Cook for 1 minute to eliminate the raw flour taste.
04 - Slowly whisk in the chicken broth, then pour in the milk. Bring the mixture to a gentle simmer, stirring constantly to prevent lumps from forming.
05 - Add the orzo, dried thyme, dried parsley, salt, and black pepper. Stir well to combine. Reduce the heat to medium-low and simmer uncovered for 10–12 minutes, stirring occasionally to keep the orzo from sticking, until the pasta is al dente and the sauce has thickened.
06 - Stir in the heavy cream, cooked chicken, and frozen peas. Continue simmering for 3–5 more minutes until the chicken is heated through and the peas are tender. Taste and adjust seasoning as needed.
07 - Remove the pot from the heat and let it sit for 2–3 minutes so the sauce finishes thickening. Garnish with extra parsley and serve warm.