Start by patting your cod fillets dry with paper towels. Season both sides with salt and pepper. Lightly dredge the fillets in flour, shaking off any excess.
In a large skillet, melt 1 tablespoon of butter over medium-high heat. Add the cod fillets and cook for about 3-4 minutes on each side until golden brown. Remove from skillet and set aside.
In the same skillet, add the remaining 2 tablespoons of butter. Once melted, add the minced garlic and sauté for about 30 seconds until fragrant.
Pour in the heavy cream, stirring continuously. Add the lemon juice and Italian seasoning. Bring to a gentle simmer, allowing it to thicken slightly.
Stir in the freshly grated parmesan cheese, allowing it to melt into the sauce. Taste and adjust seasoning as needed.
Gently return the cod fillets to the skillet, spooning the creamy sauce over them. Cook for an additional 1-2 minutes to heat through. Garnish with chopped fresh parsley before serving.