To prepare sauce, melt butter in a medium saucepan.
Add flour, stirring well with a whisk. Gradually add milk, pepper, and salt, stirring constantly with a whisk until blended.
Place over medium heat; cook until thick (about 5 minutes), stirring constantly.
Remove from heat; stir in cheese.
To prepare sandwiches, layer turkey slices evenly on toast slices; pour sauce evenly over turkey, and sprinkle evenly with paprika. Top with bacon, and sprinkle with parsley.