Step 1.  Preheat oven to 325 degrees F and grease a 9 x 13 or 7 1/2  x 11 inch casserole dish.

Step 2.  Cut chicken into bite sized pieces and sprinkle with 1/2 teaspoon salt and 1/4 teaspoon black pepper.

Step 3.  Heat olive oil in a large skillet over Medium High heat.  Add chicken and cook until browned on both sides, 4-5 minutes per side.  Remove from the pan and set aside.

Step 4.  Add cream cheese cubes, mustard and mayonnaise to the pan and cook over Medium heat until melted and combined.  Add chicken back into the pan and mix to coat.

Step 5.  Punch a hole in the bag of broccoli and microwave for 3 minutes.  Add broccoli to the bottom of the casserole dish.

Step 6.  Pour chicken mixture on top of broccoli,  

Step 7.  Sprinkle cheese on top.

Step 8.  Bake for 20 minutes until cheese is melted.  Broil for a minute or two, if you want the cheese to be browned.

Step 9.  Serve immediately.