Ingredients

• 1 pound cod fillets , cut into chunks
• 3 tablespoons butter
• 2.5 tablespoons all-purpose flour
• 1.5 cups warm milk , or more as needed
• 1 cup shredded sharp white Cheddar cheese
• 1 , 10 ounce
• 0.5 cups minced onion
• 1 teaspoon salt , or to taste
• 0.5 teaspoons ground black pepper , or to taste
• 1 clove garlic , pressed
• 2 cups mashed potatoes
• 1 cup shredded yellow Cheddar cheese

Instructions

1. 1 Preheat the oven to 375 degrees F (190 degrees C).
2. 2 Arrange cod in a single layer in a large baking dish; set aside.
3. 3 Melt butter in a saucepan over medium-low heat. Whisk in flour, and stir until the mixture becomes paste-like and light golden brown, 2 to 5 minutes.
4. 4 Gradually whisk warm milk into the flour mixture and bring to a simmer over medium heat. Whisk until the sauce is thick and smooth, about 5 minutes.
5. 5 Whisk in white Cheddar cheese, then mix onion, spinach, salt, and black pepper into the sauce.
6. 6 Remove saucepan from heat and stir in garlic. If sauce is too thick, stir in more warm milk, 1 tablespoon at a time.
7. 7 Pour sauce over fish in baking dish.
8. 8 Layer mashed potatoes on top.
9. 9 Bake in the preheated oven for 30 minutes, then sprinkle with yellow Cheddar cheese. Continue baking until fish is easily flaked with a fork, 15 to 20 minutes more.

Nutrition per serving