The Perfect Post-Christmas Comfort Food: Leftover Roast Potatoes with Homemade Cheese Sauce

After the whirlwind of Christmas feasting, the fridge is often packed with leftovers.

While the turkey, stuffing, and pigs in blankets are likely the stars of the show, there’s something magical about repurposing humble roast potatoes. 

Pair them with a luscious homemade cheese sauce, and you’ve got a dish that’s equal parts indulgent and comforting.

Here’s how to transform those crispy spuds into a post-Christmas treat that’s quick, easy, and oh-so-satisfying.

Why Roast Potatoes Deserve a Second Life

Roast potatoes are a staple of the British Christmas dinner, golden and crispy on the outside, fluffy on the inside. But reheating them can sometimes be tricky—no one wants soggy spuds. Pairing them with a creamy cheese sauce not only revives their flavour but elevates them into a rich and hearty snack or side dish.

The Recipe

Ingredients

For the cheese sauce:

25g (2 tbsp) butter

25g (2 tbsp) plain flour

300ml (1 ¼ cups) whole milk

100g (1 cup) mature cheddar cheese, grated

50g (½ cup) Parmesan cheese, grated (optional)

1 tsp Dijon mustard

A pinch of nutmeg (optional)

Salt and black pepper to taste

For the potatoes:

Leftover roast potatoes (as many as you like)

Olive oil (if reheating in the oven)

Method

Reheat the Roast Potatoes

Oven Method: Preheat your oven to 180°C (350°F). Spread the potatoes on a baking tray, drizzle with a little olive oil, and bake for 10–15 minutes until hot and crispy.

Air Fryer Method: Place the potatoes in an air fryer at 180°C for about 5–8 minutes.

Pan Method: Heat a non-stick pan over medium heat and fry the potatoes with a touch of oil until they regain their crispiness.

Make the Cheese Sauce

Melt the butter in a saucepan over medium heat. Add the flour and whisk continuously for 1–2 minutes to form a roux.

Gradually pour in the milk, whisking constantly to avoid lumps. Cook until the sauce thickens and coats the back of a spoon.

Stir in the cheddar cheese, Parmesan (if using), Dijon mustard, and a pinch of nutmeg. Season with salt and pepper to taste.

Serve

Pile the reheated roast potatoes onto a serving dish or individual bowls.

Generously drizzle the warm cheese sauce over the top.

For a festive touch, sprinkle with chopped chives, crispy bacon bits, or a dusting of smoked paprika.

Why You’ll Love This Dish

This recipe is the ultimate comfort food, perfect for lazy days between Christmas and New Year. The creamy cheese sauce adds richness, while the crispy potatoes bring texture and warmth. It’s a fantastic way to reduce food waste while treating yourself to something indulgent.

Customise It

Add Veggies: Toss in some leftover roasted Brussels sprouts, carrots, or parsnips for a colourful twist.

Spice It Up: Stir a pinch of chilli flakes or a dash of hot sauce into the cheese sauce for a kick.

Make It a Meal: Top with shredded leftover turkey or ham for a hearty dinner.

Whether you’re snuggled on the sofa with a good film or sharing a casual meal with family, this dish is sure to hit the spot. So, dig out those leftover spuds and whip up a batch of cheese sauce—you might just start a new post-Christmas tradition!

Happy feasting! (I ate this meal last night. Trust me, you will love it!_ 

Tips for Making Homemade Sauces for Christmas Meals

The holiday season is upon us, and nothing completes a Christmas feast quite like the perfect homemade sauce. 

With the right sauces, any Christmas meal, whether a traditional roast or something more unique, can be elevated to another level. 

Here’s a guide to crafting a few classic, delicious homemade sauces, along with tips to make your cooking seamless and stress-free!

1. Plan Your Sauce Selections Thoughtfully

Begin by planning your sauces based on the flavours that will complement your main courses and sides. Think about the richness of a roast turkey, the tenderness of Christmas ham, or the satisfying heft of a nut roast. Each main course pairs wonderfully with distinct sauces, so consider classics like cranberry, bread sauce, or even a rich, creamy mushroom sauce to add depth.

2. Stock up on the Essentials

For most Christmas sauces, you’ll need a solid base of ingredients, such as:

High-quality stock (vegetable, chicken, or beef) – A well-made stock can enhance flavour in gravies, bread sauce, and jus.

Fresh herbs and spices – Festive herbs like rosemary, thyme, and sage add holiday flavour. Don’t forget nutmeg and cloves for those warm, seasonal notes.

Butter and cream – Ideal for creating creamy, luscious sauces and balancing the acidity of others.

Seasonal fruits – Cranberries, oranges, and apples work wonders for Christmas sauces.

3. Mastering the Classic Gravy

A homemade gravy is the heart of many Christmas meals. The key to a luscious, velvety gravy is to deglaze the roasting pan. After roasting your meat, use red wine, white wine, or a splash of brandy to scrape up all those delicious browned bits (the fond) and add a rich depth to the sauce.

Once deglazed, add stock and simmer with a few sprigs of thyme and bay leaves for added flavour. Thicken with a roux (equal parts butter and flour) and adjust seasoning.

Tip: Create an Advance Batch

Make a batch of gravy a few days before Christmas to reduce the cooking stress on the day, and keep it in the fridge. Simply reheat and add any meat juices to boost flavour.

4. Whipping Up the Perfect Cranberry Sauce

Cranberry sauce is a holiday staple that’s easy to make and miles better than store-bought. Simply simmer fresh or frozen cranberries with sugar and a splash of orange juice for zest and brightness. If you like a twist, add a splash of port or a pinch of cinnamon for added warmth.

Tip: Balance Acidity and Sweetness

Cranberries are naturally tart, so balance them with the right amount of sugar. Taste as you go and adjust, keeping in mind that a little acidity complements the richness of roasted meats beautifully.

5. Luxurious Bread Sauce for Tradition

Bread sauce might sound simple, but it’s a comforting British classic. Start with milk infused with an onion studded with cloves, a bay leaf, and a touch of nutmeg. Add torn white bread (crust removed) to the milk until it thickens, then stir in a knob of butter and a pinch of salt to finish.

Tip: Add Richness with Cream

For an extra indulgent bread sauce, add a splash of double cream just before serving. This adds a silky, luxurious texture that pairs perfectly with turkey and other roasts.

6. Creating a Flavourful Jus

If you’re after something a little more refined than gravy, a jus (essentially a reduced sauce) can be the perfect accompaniment. A jus starts with a good-quality stock simmered until it thickens. A splash of red wine, port, or balsamic vinegar can add a touch of acidity and complexity.

Tip: Patience is Key

Allow plenty of time to reduce the sauce slowly, as this will intensify the flavours. You’re aiming for a thick, glossy texture that coats the back of a spoon.

7. Experiment with Fruit Sauces

For something unique, try experimenting with other fruit-based sauces. Apple and sage sauce pairs beautifully with pork, while redcurrant and rosemary sauce is wonderful with lamb. These sauces offer a festive balance of sweet and savoury and can often be made ahead.

8. Prepping Sauces in Advance

Most sauces, especially gravies, cranberry sauce, and jus, can be made a day or two ahead, saving you time on Christmas Day. Store them in airtight containers in the fridge and gently reheat before serving. Cranberry sauce, in particular, can be made weeks in advance and kept refrigerated or even frozen for ultimate convenience.

Final Thoughts

Homemade sauces add a personal touch to your Christmas dinner, and with a little preparation, they can be stress-free too. Remember, it’s all about balancing flavours and preparing ahead where possible. Take your time to simmer, season, and taste, and your sauces will surely be the stars of your holiday table.

Happy cooking and a saucy, merry Christmas!