In this video, you’ll see how to make a simple seafood casserole starring cod fillets, wilted spinach, and mashed potatoes. It’s so easy to prepare. You’ll lay down fresh cod fillets in the bottom of a casserole dish, followed by layers of spinach, a simple homemade white sauce, and potatoes. In a special bonus moment, you’ll also see Chef John’s plop-and-spread technique for creating the perfect mashed potato top. Watch the video, then get the recipe for Chef John’s Fisherman’s Pie. Garnish with fresh herbs if you like.