Melt the butter in a large skillet or pot over medium heat. Add the diced onion and cook until softened, about 3-4 minutes. Add the garlic and cook for another minute until fragrant.

Add the diced chicken breast to the skillet. Season with salt, pepper, and dried thyme. Cook until the chicken is browned on the outside and cooked through.

Sprinkle the flour over the chicken and vegetables, stirring constantly for 1 minute to cook off the raw flour taste.

Slowly pour in the chicken broth and heavy cream, stirring constantly to prevent lumps. Bring the mixture to a simmer.

Add the uncooked orzo pasta and mixed vegetables. Reduce heat to low, cover, and simmer for about 10-12 minutes, or until the orzo is tender and the sauce has thickened.

Remove from heat and let it sit for a few minutes. The sauce will continue to thicken as it cools. Garnish with fresh parsley before serving.