Cook broccoli in salted water (1 tsp. salt) according to directions on the package. Drain water off the broccoli and set the water aside for later.
In a buttered casserole (about 2 qt. size), add 1/3 of the broccoli first, then 1/3 of the crumbs next, then 1/3 of the cheese. Repeat, making a second layer of each. Repeat, making a third layer of each.
In a separate bowl, add the milk to the beaten eggs and enough of the water left over from cooking the broccoli so that you end up with 4 1/2 cups total of the milk/egg/broccoli water mixture--stir with a spoon. Pour that liquid over the top of everything in the casserole. Crush the Ritz crackers and sprinkle over the top. Cover loosely with foil. Bake at 325 degrees for 25 minutes or until a knife inserted comes out clean.