In a large pot melt the remaining 4 Tbsp. of butter. Stir in the flour over low heat to form a roux. Stir constantly for 2 minutes. Add the 3 cups milk and increase the heat, stirring with whisk until thickened (about 15 minutes). Add the chicken bouillon and continue to stir. Add contents of saute pan and season with salt, pepper and nutmeg. Simmer for 20 minutes. Stir in the evaporated milk and heat through.