BEST Baked Cod Recipe

Name: BEST Baked Cod Recipe
Ingredients: 6 cod fillets ((1/2-inch thick)); salt ((a pinch if cod is non-salted; none if cold is salted)); ground black pepper ((a pinch)); paprika ((a pinch)); 4-5 tbsp grapeseed or canola oil (divided); 4 tbsp unsalted butter; 4 1/2 tbsp all-purpose flour; 3 cups warmed milk (( 2% or whole)); ground nutmeg (a pinch (optional)); 2 1/2 cups blend of shredded cheeses (Mozzarella, Parmesan, white and yellow cheddar); 6 cherry tomatoes, halved; 8 olives ((green and/or black) ); 1/2 jalapeno, sliced; parsley or chives, chopped