008 / 75 · Crisp-Topped and Potato Comfort

Ham and Pea Scalloped Potato Supper

One 9×13 in (23×33 cm) baking dish, at least 3.5 qt/3.3 L; 6 main-dish portions · Active 35 min · Total 1 hr 40 min

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Thin potato slices soften first in the sauce, then finish in the oven with cubes of fully cooked ham and peas. Starting the potatoes on the stove makes this a more dependable supper than layering thick raw slices into cold milk. A modest cheddar finish browns across the top without hiding the overlapping rounds.

Jump to ingredients

Drawn creamy scalloped potatoes with ham cubes, peas and a lightly golden cheddar top.

Uniform slices make a useful promise

Aim for slices about three millimeters thick. A sharp knife and a potato with one stable flat side are enough; there is no need to introduce an unfamiliar mandoline. A mixture of paper-thin slivers and thick chunks cannot finish together. Keep the slices in a bowl of cold water while cutting, then drain before adding to the sauce. The short simmer is a head start rather than complete cooking. Check with a knife: the slices should bend but still offer a little resistance at the center.

Give the milk a gentle heat

Use a wide saucepan so the potato slices can move through the sauce when you fold them. Stir along the bottom and turn the mixture gently instead of beating it. Milk can catch before the top appears to be boiling. A steady small simmer and frequent attention keep the sauce smooth. The potatoes release starch as they cook, so the sauce will thicken further before and during the bake. Do not add extra flour simply because it looks loose in the first minute.

Ham arrives with a history

Buy fully cooked ham and read its opening or cooking date before planning leftovers. Cut it into small cubes that distribute through the potatoes instead of thick slabs that slip off a spoon. A new layer of cheese and a trip through the oven do not reset its refrigerated deadline. Serve the finished pan with a broad spoon, reaching through the potato layers so the ham and peas are divided fairly. Tender potatoes and a golden top are useful texture cues, but the mixed casserole still needs a thermometer check at the center.

Ingredients

  • 2 lb waxy or all-purpose potatoes, peeled and sliced 1/8 in/3 mm thick (900 g prepared)
  • 6 cups cold water (1.4 L), for holding potato slices, discarded
  • 2 tablespoons butter (30 g)
  • 1 medium onion, finely chopped (150 g)
  • 2 tablespoons all-purpose flour (18 g)
  • 2 1/2 cups milk (600 ml)
  • 1/2 cup low-sodium chicken stock (120 ml)
  • 1 teaspoon Dijon mustard (5 g)
  • 1/4 teaspoon black pepper
  • 12 oz fully cooked ham, safely chilled, cut in 1/2-in/1-cm cubes (340 g)
  • 1 cup frozen peas (140 g)
  • 3 oz cheddar, grated (85 g)

Set out

Oven, 9×13 in (23×33 cm) baking dish, at least 3.5 qt/3.3 L, Large wide saucepan, at least 4 qt/3.8 L, Knife and stable board, Mixing bowl, Whisk, Broad spoon, Rimmed baking sheet, Food thermometer, Suitable foil if the topping colors before the center finishes

Allergens

Milk, Wheat, Mustard; check ham and stock labels. Check labels and substitutions.

Make it

  1. Heat the oven to 375°F (190°C). Put the baking dish on a rimmed sheet. Hold potato slices in their cold water while cutting, then drain thoroughly.
  2. Melt butter in the wide saucepan over medium-low heat. Cook onion 6–8 minutes until soft. Stir in flour for 1 minute. Gradually whisk in milk and stock, add mustard and pepper and bring to a gentle simmer.
  3. Fold in drained potato slices. Simmer gently for 8–10 minutes, folding and scraping the bottom regularly, until the slices begin to bend but are not fully tender. Keep the heat low enough that the milk does not catch.
  4. Fold in ham and frozen peas. Transfer everything to the baking dish, distributing slices and ham evenly. Cover with suitable foil and bake 25 minutes. Remove foil, scatter cheddar and bake 15–20 minutes more until a knife slides easily through central potato slices and the center and several other spots reach 165°F (74°C).
  5. Rest 10 minutes, then spoon into six portions.

A short rest is part of the supper

Ten minutes lets the sauce settle around the slices. It does not produce a firm gratin to cut into perfect blocks; this remains a creamy spooned main dish.

A useful detail

The 100-minute total includes slicing, the saucepan stage, up to 45 minutes baking and the 10-minute rest. No added salt is required in the base: ham, stock, mustard and cheese already contribute seasoning.

Another way

  • Replace peas with 140 g frozen chopped green beans. Simmer them in the sauce for their package cooking time before transferring to the dish, and add that time if longer than the base method.

Keep it well

Divide leftovers into shallow containers and refrigerate within 2 hours, or 1 hour above 90°F (32°C), at 40°F (4°C) or below. Use within 3 days of the ham’s original cooking or opening, or its earlier package deadline. Reheat portions to 165°F (74°C). This milk-and-potato bake is best refrigerated rather than frozen, which can make the sauce separate and potatoes grainy.