Steam the green beans and vegetables for 5-10 minutes or until they are soft but not mushy.

Preheat the oven to 400 degrees. Spray a 9 x 13 inch pan with cooking spray.

Place 2 tablespoons of butter in a medium microwave safe dish and heat for 30 seconds. Add the breadcrumbs and mix. Stir in the mozzarella cheese and black pepper and set aside.

Add the remaining butter to a large saute pan and melt over medium heat.

Add the garlic and cook for one minute, stirring frequently.

Sprinkle the pan with the flour and cook, stirring, for one minute.

Slowly add the half and half while whisking the mixture. Bring to a boil, then reduce heat and simme, whisking occasionally, about 5 minutes.

Stir in the Parmesan, mustard powder, and 2 teaspoons of salt. Remove from heat.

Spread a third of the cream mixture to the bottom of the baking dish. Place the vegetables in the dish on top of the mixture. Pour the remaining sauce on top of the vegetables.

Sprinkle with the breadcrumb mix.

Bake for 25-30 minutes or until the sauce is bubbling.