In a separate large pot, melt 1 Tbsp. butter. Add onion, carrots, and celery. Saute until tender. Add garlic, saute.
Cut chicken into cubes and add to pot. Once cooked, add chicken broth, thyme, marjoram, sage, and rosemary and season with salt and pepper.
Increase heat to medium/high and bring to a boil. Cover for 10 minutes or until chicken is cooked through.
Reduce heat to low and add rice mixture to soup.
In a separate saucepan, melt remaining 6 Tbsp. butter over medium heat. Add flour and cook, whisking constantly. While whisking, slowly add milk into flour. Mix. Cook mix until it thickens. Once thickened, add to soup.