After you cook and cube the chicken you can go head and dice the bell pepper and make sure you have the broth and evaporated milk opened.
Now in the bottom of a stock pot melt the stick of butter and add the green bell pepper and cook until aldente. Now add the flour and stir until it is like a paste. Add chicken broth and evaporated milk while still stirring. You can go head and add chicken and pimentos. Cook until it boils and then simmer for about 15-20 mins. Now you can go ahead and start the rice on the side. The sauce will thicken as it cools. You can pull some out and freeze it for another time or you can serve it. You can add the rice or you can pour it over the rice which ever you prefer.