Place butter into a small saucepan. Place over medium heat and melt butter. Do not scorch or burn.

Add flour. Whisk to make a roux.

Reduce heat to low and cook, stirring frequently, about 3 minutes or until roux foams. Remove from heat and set aside.

In a separate medium saucepan, combine chicken broth and lemon juice.

Place over medium heat and bring to a boil.

Whisk in roux.

Remove pan from heat.

Add wine. Continue to whisk until sauce is smooth and silky.

Refrigerate sauce, in a sealed container, up to 3 days, if not using right away.

Preheat a grill or broiler. If using a grill, also preheat the oven to 450°F.

Place a saucepan of water over medium high heat and bring to a boil.

Add broccoli. Cook just until bright green and tender-crisp.

Immediately plunge broccoli into ice water to stop the cooking.

Drain and pat dry.

Use a meat mallet, flatten chicken to a uniform thickness of 1/2 to 3/4-inch.

Place flattened chicken on a plate and coat with olive oil.

Place bread crumbs into a large shallow bowl.

Dredge both sides of each chicken breast in bread crumbs.

Place chicken on grill or under broiler and cook about 4 minutes per side, to an internal temperature of 165 degrees. (Insert thermometer horizontally for an accurate reading.) If using the broiler, set oven at 450°F when you remove the chicken.

Pour prepared sauce into a large skillet.

Add prosciutto, red pepper flakes and garlic. Place over medium heat and bring to a boil.

Add broccoli and mushrooms. Continue to cook until sauce thickens and reduces by about 1/3.

In a small bowl, mix cheeses together.

Place cooked chicken on a shallow baking pan.

Top each piece with 1/2 cup combined cheeses.

Place in preheated oven and bake until cheese is melted, about 4 minutes.

Transfer chicken to serving plates.

Use a slotted spoon to evenly distribute broccoli and mushrooms over chicken.

Pour on remaining sauce, to taste.

Serve immediately.