In a small pot with a fitted lid, bring the water to boil. Add in the raw rice. Turn the heat down to low, fit the lid on tight. and set a timer for 12 minutes. Turn the heat off when the timer goes off. Let it sit till needed.
Rinse and cut up the broccoli. Put the broccoli in a small pot that has a fitted lid. Add enough water for the broccoli to just be sitting in it. The broccoli should NOT be submerged. Fit the lid on and turn the heat on high. Once there is steam, and the water is boiling. After 3-4 minutes, test with a fork. The broccoli needs to be fork tender, but not mushy or crunchy. Drain the water off.
Lightly spray a 9x13 dish with oil. Spread the rice out in an even layer.
Spread the broccoli over the rice, and the chicken over the broccoli.
For the sauce, mix all the ingredients except the broth, in a large mixing bowl.
Slowly add the broth while stirring. You may not need or wish to add all the broth. You don't want it too runny. The broth's purpose is to thin it a little, so it spreads easier. I almost always add all the broth.
Spread the sauce over the other 3 layers.
Use a fork to blend the Panko with seasonings. Evenly sprinkle the crumbs over the top.
Bake at 350° for 30 minutes.