Steam broccoli for 5 minutes until crisp-tender.
Saute mushrooms in 2 T. butter until tender.
In greased 9x13 baking dish, layer chicken, mushrooms, water chestnuts and broccoli.
For the sauce, melt 4 T. butter in skillet.
Stir in flour, seasoned salt and pepper until smooth. Gradually add broth and cream.
Bring to a boil; cook and stir for 2 minutes or until thick and bubbly. Remove from heat.
Stir small amount of hot mixture into egg yolks, then whisk the yolks into the skillet. Cook and stir until heated through.
Stir in lemon juice and nutmeg. Pour sauce over broccoli, distributing evenly. Sprinkle with almonds.
Bake uncovered at 375 degrees F. for 20 minutes until bubbly around edges and heated through.