Step 1

Steam broccoli until crisp-tender; drain under cold water and set aside.

Step 2

In a skillet over medium heat, melt 1 tablespoon butter.

Step 3

Add in the mushrooms and stir/saute for 5 minutes and stir/saute for 5 minutes or until slightly tender.

Step 4

Transfer mushrooms using a slotted spoon to the container holding the broccoli (I put them all on a plate).

Step 5

Add remaining butter to skillet and let melt over medium heat.

Step 6

Add in flour and blend.

Step 7

Add in stock, mustard, thyme, salt, and pepper; whisk for about 2 minutes or until mixture thickens.

Step 8

Add in grated cheddar cheese and stir until smooth.

Step 9

Using a 4-quart casserole dish, layer half the chicken, half the vegetables; repeat the layers.

Step 10

Pour sauce over the top.

Step 11

Cover and bake at 350 degrees for 40 minutes or until bubbly.

Step 12

Stir and top with Parmesan cheese.

Step 13

Bake uncovered for 5-10 minutes or until cheese melts.