Melt butter in a saucepan.

Add flour and stir until lightly cooked, creating a roux.

Add minced onion, garlic, parsley, and green onion to the roux and sauté until softened and translucent.

Add crawfish tails to the pan and cook over low heat for about 10 minutes, stirring occasionally.

Pour in white wine and simmer until the wine is mostly absorbed and the flavors are blended.

Slowly add heavy cream, stirring constantly to incorporate it smoothly.

Simmer over low heat; do not boil.

Season to taste with salt, pepper, and paprika, adding extra paprika to enhance the color and flavor.