Make the Pimento Cheese or use a store bought version.
In a medium cast-iron skillet, heat the oil.
Add the andouille sausage and cook over medium heat, stirring, until the sausage is crispy, about 8 minutes.
Add the onion and cook, stirring, until translucent, 1 to 2 minutes.
Stir in the bell pepper and garlic and cook, stirring, 2 minutes.
Sprinkle in the flour and stir until incorporated; add the tomato and cook over moderately low heat, stirring, about 3 minutes.
Add chicken stock and bring to a simmer; cook until the gravy thickens enough to coat the back of a spoon, about 5 minutes.
Season with salt if desired.
Put cooked fries in an oven safe dish or cast-iron skillet, top with gravy, then top with crawfish. Spoon pimento cheese on top.
Bake at 450° for 5 minutes. Turn broiler on for about 30 seconds until top is browned.