Bring a large pot of water to a boil and add the linguini. Cook according to the package directions until al dente, then drain the pasta, reserving some pasta water for later.

Season the scallops with salt and pepper. Heat 2 tablespoons of oil in a frying pan over medium-high heat. Cook the scallops for about 2 minutes on each side until golden brown. Remove scallops from the pan and set them aside.

In the same pan, add the shrimp and cook until they turn pink and are no longer translucent. This should take about 2-3 minutes. Remove the shrimp and place them with the scallops.

Discard excess oil from the pan and wipe it clean. Add 2 tablespoons of oil and the butter, melting it over medium heat.

Whisk in the flour to create a roux, then slowly add the milk and stir in the Parmesan cheese. Let the sauce simmer for a few minutes, stirring frequently until it thickens.

Add the cooked scallops, shrimp, and linguini to the sauce. Toss gently to combine all the ingredients. Sprinkle with fresh herbs before serving.