Heat oven to 375F/190C. Spray a 9″x12″ casserole dish with non-stick spray. (The dish can be slightly smaller too, especially if you use the smaller amounts of ingredients.)
Bring a medium-sized pot of water to a boil and cook the broccoli just 2 minutes; then pour into a colander placed in the sink and let it drain well. Dice the ham while the broccoli drains.
Layer broccoli, ham, Mozzarella, beaten egg, salt and pepper in casserole dish.
Use a fork to “stir” the mixture just until all the ingredients are coated with egg. (It might look like there is not enough egg, but carry on!)
Bake 35-45 minutes, or until all the mixture is set and the top is starting to lightly brown. (If you use the higher amount of eggs, it will take the longer baking time, but start to check after about 30 minutes.)
Serve hot, with sour cream if desired. This can be kept in the fridge for at least a week and reheated in the microwave.