Chicken/rice/broccoli Casserole

• 2 bunches broccoli (chopped)
• 1 onion (chopped)
• 1 bunch celery (chopped)
• 1 velveeta cheese
• 1 cheese whiz
• 1 stick butter
• 1 chicken up (cut)
• 1 garlic sat (optional)
• 160 gr mushrooms (chopped)
• 60 ml crisco oil with garlic (roasted)