Set a large 1-gallon stock pot of water to a boil and add the kosher salt. Place the linguine in the pot and stir the pot until the water returns to a boil. Cook the pasta until tender, but with a bit of resistance (al dente), about 12 minutes.
While the pasta cooks, prepare the sauce. Set a 12-inch saute pan over medium-high heat. Add the butter and olive oil to the pan. Once the butter has melted, season the shrimp with 1 tablespoon of the Essence and 1/2 teaspoon of the salt and add the shrimp to the pan. Sear the shrimp until pink, about 1 minute, then turn over and cook for another minute. Remove the shrimp from the pan and set aside. Add the onions and saute until softened and lightly caramelized, about 4 to 5 minutes. Add the garlic to the pan and saute until fragrant, about 30 seconds. Add the cream, pesto, remaining tablespoon of Essence, remaining teaspoon of the salt to the pan and bring to a boil. Cook the sauce until the cream is reduced by half, about 2 minutes. Return the shrimp, linguine and the reserved cooking water to the pan and cook, tossing to incorporate for 3 to 5 minutes. Remove pan from the heat and add the parsley and parmesan cheese and toss to blend. Serve immediately.
Emeril's ESSENCE Creole Seasoning (also referred to as Bayou Blast):
Combine all ingredients thoroughly.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch