Heat the oven to 350 F. Cut asparagus into 1 inch slightly diagonal spears. 

Melt 1 tablespoon of butter in a medium saucepan or sauté pan over medium heat. Add the sliced asparagus, ½ teaspoon garlic powder and cook, 3-4 minutes stirring, until they are tender. Include a pinch of salt and cook for another 1-2 mins. Remove from heat and place aside in a med-lg mixing bowl. 

Using the same pan, add another tablespoon of butter. Add salmon, 2 teaspoons garlic powder & paprika, 2-3 pinches of salt and cook 3-4 minutes, do not overcrowd the pan. Remove from heat and place in the same mixing bowl with the asparagus.

Next, included another tablespoon of butter. Next place shrimp, 2 teaspoons of garlic & paprika and 2-3 pinches of salt and cook for 3 minutes. Remove from heat and place in the same mixing bowl with the asparagus & salmon.

In a medium size pot, over medium-low heat add heavy cream & cream cheese and stir for 2-3 minutes. 

Gradually add white cheddar/ mozzarella mix cheese and continue to stir. Add the remaining butter to a saucepan and place it over medium-low heat; stir in flour until smooth and bubbly. Continue cooking, stirring, for 2 minutes.

Next, add parsley & tarragon and mix until the sauce is thickened and bubbly. Stir in the salt & pepper and continue to stir, allowing to simmer on low heat. 

Gently pour the sauce into the seafood and asparagus mixture and mix well. 

Spray a 1 1/2-quart casserole with cooking spray. 

 Next, pour seafood and asparagus mixture into the baking dish, layering with spring onions. 

In a small bowl or measuring cup, mix panko bread crumbs, parmesan cheese & dill and sprinkle mixture evenly on top. 

Bake in a preheated oven for 15-17 minutes.

Turn on the broiler for 1-2 minute to achieve a brown and crispy top.

Serve immediately and enjoy.