Preheat your oven to broil.

In a medium saucepan, sauté the butter, mushrooms, and broccoli until cooked.

Add the flour and cook for 2 minutes. Whisk in the milk, mustard, and salt.

Incorporate the cream cheese until melted. Stir in 1/4 cup of shredded Jarlsberg cheese (save the other half for topping).

Heat through until everything is melted and place in oven safe dish. Top with extra cheese and broil for 5 minutes until golden brown.

Serve hot with crackers, vegetables, and bread.