5 slices bacon
1 small onion, chopped
2 tablespoons all-purpose flour
1 1/4 cups milk
1 1/4 cups low-sodium chicken broth
1 1/4 cups grated muenster or monterey jack cheese
Kosher salt and freshly ground pepper
4 thick slices white bread, toasted
Dijon mustard, for spreading
1 tomato, sliced
3 cups shredded or sliced roast turkey or rotisserie chicken
1/4 cup chopped fresh parsley