Leftover Brussels Sprouts Mac and Cheese – a creamy, comforting bake that turns your Christmas sprouts into an easy family meal. Simple, budget-friendly and packed with flavour.
If you enjoy Brussels sprouts, this is a really handy way to use up any leftovers. Stirring them into a simple mac and cheese gives you an easy, comforting meal that still lets the sprouts add their gentle flavour and texture.
This Brussels Sprouts Mac and Cheese is straightforward, creamy and ideal for a relaxed midweek or Boxing Day dinner. The pasta, cheese sauce and sprouts come together in a way that feels cosy without being heavy, and it’s a great option when you want something practical but tasty.
Roasted, boiled, pan-fried, or steamed sprouts all work well here, so whatever you have in the fridge can go straight in. It’s a no-fuss way to make the most of leftovers while still enjoying a bit of sprout goodness.
Why I Love Mac and Cheese with Leftover Brussels Sprouts
- It’s a brilliant way to use up those extra Christmas Brussels sprouts.
- The sprouts bring a bit of festive flavour without taking over the dish.
- It turns post-Christmas leftovers into an easy, comforting meal.
- Works with whatever sprouts you’ve cooked for Christmas dinner — roasted, steamed, boiled or pan-fried.
- It’s a simple, no-stress recipe for that slower, in-between-Christmas week.
- You can add some of your other Christmas leftovers, or serve it on the side of your Boxing Day turkey sandwich.
Ingredients For Mac and Cheese with Sprouts
Cooked Brussels sprouts
Butter
Garlic puree
Plain flour
Milk
English mustard
Salt and black pepper
Mature cheddar
Mozzarella
Macaroni pasta – straight or elbow macaroni is fine
You’ll Also Need
I use a jug, a large pan, a colander, a balloon whisk, a large ovenproof dish, a sharp knife, a chopping board and a wooden spoon.
How to Make Leftover Brussels Sprouts Mac and Cheese – Step-by-Step Instructions
Full, easy-to-follow instructions and quantities are available in the recipe card at the bottom of this post.
Step One
Cook the pasta according to the packet instructions until just tender. Drain well, rinse briefly under cold water to stop it cooking further, and set aside.
Step Two
Melt the butter and garlic purée in a large, flameproof pan over a medium heat.
Step Three
Reduce the heat and sprinkle in the flour. Whisk continuously until it forms a smooth, thick paste (a roux) with no lumps.
Step Four
Begin adding the milk slowly, a splash at a time, whisking well after each addition. This helps create a smooth sauce with no gritty bits.
Step Five
Once all the milk is incorporated, turn the heat back up to medium and bring the sauce to a gentle simmer, whisking often to stop it catching.
Step Six
When the sauce is simmering, keep whisking for around 3 minutes until it has thickened to a creamy consistency.
Step Seven
Remove the pan from the heat. Preheat the oven to 180°C (fan) and find an ovenproof dish so it’s ready to go.
Step Eight
Whisk in the salt, pepper and mustard. Add the sliced, cooked Brussels sprouts and stir them through so they’re evenly distributed.
Step Nine
Add the cooked pasta and most of the grated cheese. Stir carefully until the cheese melts into the sauce and everything is well coated.
Step Ten
Pour the mixture into the prepared ovenproof dish and spread it out evenly.
Step Eleven
Sprinkle the remaining cheese over the top.
Step Twelve
Bake for 20–25 minutes, or until the top is golden, crisp in places, and the sauce is bubbling around the edges. Let it sit for a couple of minutes before serving.
Serving Suggestions
I love my Macaroni cheese with sprouts just as it is, straight from the oven. But it also makes a great side dish for a burger, steak or leftover roast turkey sandwich.
You can also serve it with other leftover Christmas potatoes and veggies or some bread and butter.
Variations
Chuck in more leftovers!
You can even add bacon if you’ve cooked your sprouts with it. You can also add other cheeses like Parmesan and Gruyère to your sharp cheddar.
If you like a crispier top, sprinkle on some breadcrumbs before baking for that classic Mac taste and texture.
Storage
Store leftovers in the fridge for a day or two and reheat in the oven or microwave until piping hot. If you are worried about it drying out, add a splash of water to the pan and cover loosely with foil before putting it in the oven. Don’t put foil in the microwave!
Other Recipes
If you like this leftover Brussels sprouts recipe, you might also want to try:
Leftover Brussels Sprouts Mac and Cheese
Ingredients
- 300 g cooked sprouts (sliced)
- 40 g butter
- 1 Tsp garlic puree
- 40 g plain flour
- 500 g milk
- 1 Tbsp English mustard
- Pinch salt and pepper
- 150 g mature cheddar (grated)
- 150 g mozzarella (grated)
- 300 g macaroni pasta
Instructions
- Cook the pasta according to the packet instructions, then drain, rinse and set aside.
- Melt the butter and garlic purée in a large flameproof pan over a medium heat.
- Reduce the heat and add the flour.
- Whisk until it forms a smooth paste.
- Start adding the milk, whisking in a little at a time until fully combined.
- Increase the heat and bring the sauce to a gentle simmer, whisking often.
- Once simmering, keep whisking for about 3 minutes until the sauce has thickened.
- Take the pan off the heat.
- Preheat the oven to 180°C (fan) and get an ovenproof dish ready.
- Whisk in the salt, pepper and mustard, then stir through the sliced cooked Brussels sprouts.
- Add the pasta and most of the cheese.
- Stir gently until the cheese has melted and everything is coated in the sauce.
- Tip the mixture into the ovenproof dish and spread it out evenly.
- Sprinkle over the remaining cheese.
- Bake for 20–25 minutes, until the top is golden and bubbling.
Notes
- Use as many sprouts as you’ve got
- Semi-skimmed or whole milk is fine
Any nutritional information is given as a general guide only and may not be accurate. The information is provided using an online calculator and is specific to my ingredients. Please make your own calculations if you want precise information.
