Chicken Prosciutto With Mushroom Sauce

• 9 baking (pan)
• 3 chicken breasts (whole)
• 1/2 swiss cheese
• 475 ml sauce over the broccoli
• 170 gr pkg broccoli (frozen)
• 240 ml chicken broth
• 80 gr mushrooms (sliced fresh)
• 70 gr butter
• 70 gr butter
• 60 gr swiss cheese (grated)