In a Dutch oven or heavy pot, heat the butter over medium-high heat until melted. Add the onion and sauté for 7-10 minutes until it becomes softened.
Meanwhile, bring a pot of water to a boil and add the pasta. Cook until it reaches the desired level of firmness (al dente), then drain and set aside.
Add the garlic, paprika, salt, garlic powder, cayenne pepper, oregano, thyme, and pepper to the pot. Stir continuously for 30 seconds, then pour in the wine. Allow it to cook until most of the wine has evaporated.
In a small bowl, whisk together the cornstarch and ¼ cup of milk. Add this mixture to the pot and slowly stir in the remaining milk. Reduce the heat to medium and cook for 5 minutes until the sauce thickens.
Stir in the crawfish tails and cook for an additional 2 minutes. Incorporate the lemon juice, green onion, and parsley, stirring well to combine. Remove the pot from the heat and gently fold in the Parmesan cheese.
Serve the sauce alongside the cooked pasta. Enjoy this delightful dish!