Preheat oven to 160 degrees C.

Make up white sauce by combing first 5 ingredients and heating on low until it thickens.  Take off heat.

Grease an oven proof casserole dish.  Combine pasta, ham, chicken and chopped vegetables in the dish.

Add the eggs to the white sauce one at a time and stir well to combine.  Add the sauce to the other ingredients and combine.

Sprinkle with cheese if using.