1 lb potatoes, peeled and chopped into large chunks
4 tsp butter, divided
1 cup whole milk, divided
1 cup carrots, sliced (or use frozen)
1 cup sweet onion, diced
1 bay leaf
1 garlic clove, minced
1 sprig fresh thyme or 1/4 tsp dried thyme
1/2 lb cod, or other white fish
1/2 lb shrimp, peeled & deveined
2 cups frozen peas
2 cups spinach
2 Tbsp plain (all-purpose) flour
1/4 cup cheddar cheese, grated
sea salt & pepper
Preheat oven to 400°. Place potatoes in a pan and cover with cold water. Bring to a boil, reduce heat to medium and boil for about 15 minutes or until fork tender. Drain, return to pot, add 1/4 cup milk, 2 tsp butter, salt & pepper. Using a hand mixer, blend to mash and incorporate flavors. Set aside.
While potatoes are boiling, steam carrots and onion until fork tender. Drain and set aside.
Heat 3/4 cup milk, bay leaf, garlic, and thyme in a saucepan over medium heat. Reduce to medium-low and let simmer, stirring constantly to infuse flavors for about 3 minutes. Be careful not to burn this mixture.
Reduce heat to low, add cod to pan and poach for about 4 minutes, then add shrimp. Cook for another 1-2 minutes, or until shrimp is pink. Remove from heat. Do not discard milk, you will be using it later. Discard bay leaf and thyme sprig (if applicable).
Remove cod & shrimp from the milk mixture & place in the bottom of an 9X13 baking dish. Add the reserved carrots & onions; top with peas & spinach.
Pour milk into a small bowl and set aside. Melt the remaining 2 tsp butter in the saucepan over medium heat. Add flour and heat through, stirring constantly for about 1 minute. Slowly add in the reserved milk, whisking continuously. Sauce will begin to thicken after another 1-2 minutes. Remove from heat and stir in half of the grated cheese and a pinch of black pepper.
Pour the sauce over the fish mixture in the baking dish. Top with mashed potatoes using a fork to spread out as evenly as possible . Sprinkle the remaining cheese over the top and bake for 15-20 minutes. (Or until cheese is melted and golden.) Divide into 4 equal servings and enjoy!