Cook bacon until crisp. Drain on paper towel; crumble and set aside.
In nonstick Dutch oven or 4-quart saucepan, mix chicken, rice with contents of seasoning packet and broth. Heat to boiling. Reduce heat to low; cover and simmer 5 to 10 minutes or until rice is tender.
In small jar with tight-fitting lid, shake 1 cup of the milk and the flour until well blended.
Add flour mixture, remaining 3 cups milk, the bacon, pimientos and sherry to rice mixture; cook over medium heat, stirring constantly, until soup is bubbly and thickened and chicken is no longer pink in center. If desired, season to taste with salt and pepper.