- Melt the butter in a large skillet over medium-low heat.
- Add the mushrooms and green pepper and cook, stir continuously for 8 minutes or until the pepper is crisp and tender.
- Add the flour and black pepper; mix well and continue to cook, stir constantly for 3 minutes. Add the hot milk and chicken stock base and bring to a boil, stirring constantly.
- Reduce the heat to low and simmer, stir continuously until slightly thickened for just 15 minutes. Add the chicken and pimiento and continue stirring until heated through.
- To serve, spoon 1/2 cup of the mixture over each slice of whole wheat toast.