Delia Smith Potato Gratin

When you need a side that quietly steals the show:
Delia Smith’s Potato Gratin is creamy, cheesy, and unapologetically rich — the kind of thing you keep “just for the roast,” then end up eating straight from the dish with a fork.

Made this for Sunday dinner once.
Forgot the roast existed.

Why You’ll Love It

• Thin, tender layers bathed in silky cheese sauce
• Crusty golden top with a creamy, comforting middle
• No fancy ingredients — just real pantry staples
• Works with roasts, grilled meats, or on its own
• Can be made ahead and reheated beautifully

Ingredients You’ll Need

• 4 medium russet potatoes, thinly sliced
• 1 medium onion, sliced into rings
• Salt and ground black pepper
• 3 tablespoons butter
• 3 tablespoons all-purpose flour
• ½ teaspoon salt
• 2 cups milk
• 1½ cups shredded Cheddar cheese

How to Make Delia’s Potato Gratin

1. Oven on: 400°F (200°C).
   Butter a 1-quart baking dish.
2. Layer it up: Spread half the sliced potatoes in the dish.
   Season well.
   Scatter the onion rings across.
   Top with the rest of the potatoes.
   Season again.
3. Make the sauce: Melt the butter in a saucepan over medium-low heat.
   Whisk in the flour and ½ tsp salt — cook for a minute to knock out the raw flour taste.
4. Slowly whisk in the milk — bit by bit — whisking after each splash.
   Once smooth, keep cooking and stirring 3–5 minutes till it thickens.
5. Stir in all the cheese until melted and silky.
6. Assemble and bake: Pour the cheese sauce evenly over the potatoes.
   Cover tightly with foil.
7. Bake for 90 minutes — bubbling, golden, and the potatoes should be fork-tender.
8. Let it rest 10 minutes before serving.

Common Mistakes to Dodge

• Uneven potato slices: cuts uneven = uneven cooking.
• Skimping on seasoning: season each layer. It matters.
• Rushing the rest: Resting thickens the sauce naturally.

What to Serve It With

• Roast chicken or beef
• Green salad with vinaigrette
• Buttered peas or steamed broccoli
• Grilled sausages

Storage and Leftovers

• Fridge: Cool fully, store airtight up to 3 days.
• Freezer: Wrap tightly, freeze up to 3 months.
• Reheat: Oven 350°F for 15–20 mins or microwave, covered.

FREQUENTLY ASKED QUESTIONS

Why does my potato gratin get watery?
Potatoes not dried enough — pat them well before layering.

How do you get a crispy top?
Uncover for the last 10 minutes of baking. Or scatter a little extra cheese or breadcrumbs over the top.

Can you make it ahead?
Yes — assemble fully, refrigerate, then bake when needed. Might need an extra 10 minutes if cold from the fridge.

Best potatoes for gratin?
Russets or Yukon Golds — they soak up the sauce and go tender.

Try More Delia Smith Recipes:

• Delia Smith Spanish Chicken
• Delia Smith Paella
• Delia Smith Bacon And Egg Pie

Nutrition Facts

• Calories: 499 kcal
• Fat: 25g
• Carbs: 49g
• Protein: 20g