038 / 75 · A Vegetable-Led Table
Potato and Spinach Layer Bake
4 generous portions of layered potatoes and spinach · Active 25 min · Total 2 hr
Print recipe · PDFThin potato slices and squeezed frozen spinach make a substantial layered bake with a simple milk sauce. A little cheddar on the surface gives a clear browned finish. The long oven time is deliberate: potatoes need to become tender all the way through before the dish is uncovered. A short rest afterward makes the layers easier to lift.
Slice for even cooking
Use a sharp knife to make potato slices about one-eighth of an inch thick. A mandoline is optional equipment, not a necessary purchase. Uneven slices create a dish in which the thin pieces break down while thicker ones still resist the fork. Keep the prepared potatoes in a bowl of cold water only while making the sauce, then drain well before layering. The bake needs their starch to help thicken the milk, so do not soak them for a long period or rinse repeatedly after slicing. Spread the pieces in fairly even overlapping layers rather than dropping thick piles into the corners.
Control water before adding sauce
Thaw the spinach safely in the refrigerator or microwave according to its packet. Squeeze it firmly in a clean cloth or sieve; otherwise its water dilutes the sauce between the potato layers. Break up the squeezed spinach with your fingers so it spreads in small patches. Cover the dish tightly for the first part of baking. Steam and sauce heat the potatoes while the cover prevents an early hard crust. Uncover only after a knife passes almost easily through the center. The final bake reduces the sauce slightly and browns the cheese. Judge tenderness before color, then let the dish stand so its sauce settles.
Ingredients
- 2 lb potatoes (900 g), peeled and sliced 1/8 inch/3 mm thick
- 10 oz frozen chopped spinach (300 g), thawed and squeezed well
- 2 tablespoons butter (28 g)
- 1 small onion (100 g), finely diced
- 2 1/2 tablespoons all-purpose flour (20 g)
- 2 1/2 cups milk (600 ml)
- 3/4 teaspoon fine salt (4.5 g)
- 1/4 teaspoon black pepper (0.5 g)
- 3/4 cup grated cheddar (80 g)
Set out
8 by 11-inch/20 by 28 cm baking dish, about 2 quarts/2 liters, Medium saucepan, Knife and board, Sieve or clean cloth, Foil or oven-safe cover, Food thermometer
Allergens
Milk, Wheat. Check labels and substitutions.
Make it
- Heat oven to 375°F/190°C. Thaw spinach safely and squeeze out excess water. Slice the potatoes evenly; if held briefly in water, drain them well before layering.
- Melt butter in the saucepan over medium-low heat. Cook onion for 5–6 minutes. Stir in flour for 1 minute. Gradually stir in milk, salt and pepper and simmer for 4 minutes, until lightly thickened.
- Spread a spoonful of sauce in the baking dish. Layer half the potatoes, half the spinach and half the remaining sauce. Repeat with the remaining potatoes, spinach and sauce. Cover tightly with foil or a lid.
- Bake for 55–65 minutes, until a knife passes almost easily through the center. Remove the cover, scatter cheddar over the surface and bake for 15–20 minutes more, until the potatoes are completely tender, the top is golden and the center reaches 165°F/74°C.
- Rest for 10 minutes before dividing into four portions. If the potatoes still feel firm, re-cover and bake longer rather than serving by the clock alone.
Make the oven time useful
While the covered dish bakes, prepare another planned oven item if the temperatures fit. Keep raw meat separate from ready-to-eat food and avoid crowding the oven so tightly that the potato dish cooks unevenly.
Timing
The total assumes the frozen spinach is already safely thawed. Allow extra time for thawing according to its packet; potato tenderness controls the final baking time.
A useful detail
The spinach weight is its frozen weight before squeezing. An especially deep dish or thicker potato slices take longer; the stated total assumes a shallow dish and 3 mm slices.
Another way
- Use the same frozen weight of chopped kale, thawed and squeezed. Remove tough stem pieces before layering.
- Replace half the cheddar with the same weight of grated firm cheese already in use; keep the total topping at 80 g.
Keep it well
Cool in shallow portions within 2 hours, or 1 hour above 90°F/32°C. Cover and refrigerate at 40°F/4°C or below for up to 3 days. Reheat covered to 165°F/74°C in the center. Freeze cooled portions for up to 1 month; thaw in the refrigerator before reheating.