Ingredients for - Chef John's Fisherman's Pie

1. Russet potatoes, peeled and cut into chunks 3
2. Butter 3 tablespoons
3. Freshly grated nutmeg 1 pinch
4. Salt and ground black pepper to taste 1 pinch
5. Cayenne pepper, or to taste 1 pinch
6. Milk ½ cup
7. Olive oil 2 teaspoons
8. Baby spinach leaves 12 ounces
9. Butter 3 tablespoons
10. All-purpose flour 3 tablespoons
11. Garlic, minced 2 cloves
12. Cold milk, divided 2 cups
13. Lemon zest 2 teaspoons
14. Butter 1 tablespoon
15. Salt and ground black pepper to taste 1 tablespoon
16. Cayenne pepper, or to taste 1 pinch
17. Boneless cod fillets 2 pounds
18. Lemon, juiced ½
19. Chopped fresh chives for garnish 1 tablespoon

How to cook deliciously - Chef John's Fisherman's Pie

1 . Stage

Bring a large saucepan of salted water to a boil; add potatoes to boiling water and cook until very tender, about 20 minutes. Drain well. Mash in 3 tablespoons butter until thoroughly combined. Season with nutmeg, salt, black pepper, and cayenne pepper. Mash 1/2 cup milk into potato mixture until smooth.

2 . Stage

Drizzle olive oil in a large Dutch oven over medium-high heat, add spinach, and season with a big pinch of salt. Cook, stirring occasionally, until spinach has wilted, about 1 minute. Transfer to a bowl lined with paper towels to wick away excess moisture.

3 . Stage

Heat 3 tablespoons butter and flour in a saucepan over medium heat; whisk mixture to a smooth paste. Cook, stirring constantly, until mixture has a nutty smell and is slightly browned, about 2 minutes. Add garlic; whisk until fragrant, 10 to 20 seconds.

4 . Stage

Whisk 1 cup cold milk into flour mixture; cook until thickened. Whisk in remaining 1 cup milk and lemon zest. Bring white sauce to a gentle simmer, whisking constantly; season with salt. Turn heat to very low and keep sauce warm.

5 . Stage

Preheat the oven to 375 degrees F (190 degrees C). Grease an 8x12-inch casserole dish with 1 tablespoon butter.

6 . Stage

Season buttered pan with salt, black pepper, and cayenne pepper. Lay boneless cod fillets into the pan in a single layer. Season tops of fillets with more salt, black pepper, and cayenne pepper. Spread spinach evenly over fish and drizzle with lemon juice. Spoon white sauce over spinach; give casserole dish several taps and shakes to eliminate bubbles.

7 . Stage

Drop mashed potatoes by heaping spoonfuls over the casserole and spread smoothly to cover. Place dish onto a rimmed baking sheet to catch spills.

8 . Stage

Bake in the preheated oven until bubbling, about 40 minutes. Turn on the oven's broiler and broil until potato crust has a golden brown top, about 2 minutes. Fish should flake easily. Let stand 10 minutes before serving. Garnish with a sprinkle of chives.