Creamy Spam Broccoli Casserole

• 475 ml skim milk
• 180 gr broccoli (frozen cut)
• 110 gr fat free cheddar (shredded)
• 80 gr soft bread crumbs
• 65 gr bell pepper (chopped red)
• 16 gr cornstarch
• 9 gr margarine
• 1 gr pepper