Mac and Cheese Toastie
The best mac and cheese toastie starts with cold, fridge-set macaroni cheese cut into a flat slab about 1.5cm thick. Set pasta holds together in the sealed plates, a layer of grated cheddar on each side melts into it, and an extra minute of cooking (about 5 minutes total) makes sure the centre is hot, not lukewarm.
On this page
Recipe: Mac and cheese toastie
Ingredients
- 2 slices medium white bread
- 100g cold leftover macaroni cheese, set firm from the fridge
- 30g mature cheddar, grated
- ¼ tsp English mustard powder or ½ tsp English mustard
- A pinch of smoked paprika
- 10g softened butter for the outside
Method
- Preheat the toastie maker with the lid closed.
- Turn the chilled macaroni cheese out onto a board. Cut a slab about 1.5cm thick and slightly smaller than your bread, about 9cm square for most standard machines. Save the offcuts for another toastie.
- Mix the grated cheddar with the mustard and paprika.
- Butter one side of each slice. Place one slice butter-side down on the bottom plate and scatter on half the cheddar mix, leaving a 1cm border.
- Lay the mac and cheese slab in the centre and press it down lightly with your palm so it sits flat. Cover with the remaining cheddar.
- Top with the second slice, butter-side up. Close the lid gently; it should latch without force.
- Cook for 5 minutes until deep golden. Cut and check the middle is steaming. If not, return it for another minute. Rest 1 minute before eating.
Why a cold slab works
Macaroni cheese sets firm in the fridge because the starch from the pasta and the flour in the sauce gel as they cool. That gel is your friend: a solid slab holds its shape as the lid comes down and stays in the middle, whereas warm, loose mac and cheese gets squeezed out sideways through the seal. Cold also means the slab won't go mushy before the bread is toasted.
The trade-off is heat penetration. A 1.5cm slab of pasta starts at fridge temperature, so it needs longer than a plain cheese toastie. Keeping it no thicker than 1.5cm and cooking for the full 5 minutes gets the core hot. Leftover pasta dishes should be reheated until steaming hot all the way through, and only once, so cut to check.
Leftover mac and cheese can taste a little flat because the sauce has absorbed into the pasta. The extra cheddar, mustard and paprika on the outside layers bring back the sharpness. See our best cheese for toasties guide if you want to swap in red Leicester or a smoked cheese.
Deep fill makes a real difference
This is a heavy, carb-on-carb toastie and fits best in a deep fill toastie maker, where you can use a 2.5cm slab (about 150g) and 40g cheese. Allow 6–7 minutes. In a standard shallow machine, don't go above 100g or the lid won't close cleanly and you'll fight leaks; see how to stop toasties leaking.
On a panini press, the floating hinge copes with the thickness, but the pasta isn't sealed in, so cut the slab neatly. Cook 5–6 minutes. In a frying pan, use a lid for the first 3 minutes to drive heat into the centre, then flip (details on the frying pan toastie page). The air fryer needs 170°C for 10–11 minutes, turning halfway.
Variations
- Bacon mac: 2 rashers of crisp, crumbled streaky bacon pressed onto the slab.
- Chilli mac: 2 tbsp thick leftover chilli over the slab; cut the mac to 80g. Our chilli cheese toastie has the leak control for chilli.
- Jalapeño mac: a few chopped pickled jalapeños, patted dry, with the cheddar.
- Truffle and parmesan: swap the cheddar for 20g parmesan and a few drops of truffle oil.
- Tomato: 2 thin slices of tomato, salted and blotted, on top of the slab.
Mistakes to avoid
- Using fresh, warm mac and cheese: it's too loose and will squeeze out. Chill it for at least 4 hours or overnight.
- A slab bigger than the bread: any pasta at the edges blocks the seal and burns on the crimp.
- Undercooking: a golden outside doesn't mean a hot centre. Cut and check.
- Forcing the lid: pressing hard on the latch can damage the hinge over time. Trim the slab instead.
Find more comfort-food ideas in our toastie recipes, or start from the basics with the classic cheese toastie.
FAQs
Can I use shop-bought macaroni cheese?
Yes. A chilled ready meal works well if you cook it, let it cool, then refrigerate it until firm. Straight-from-the-pack, uncooked ready meals aren't safe to use raw in a toastie.
How long does leftover mac and cheese keep?
Up to 2 days in the fridge once cooked and cooled, covered. Cool it quickly and refrigerate within about 2 hours of cooking.
Why is my mac and cheese toastie cold in the middle?
The slab is too thick or too cold for the cooking time. Keep it to 1.5cm in a standard machine, let it sit out for 10 minutes, and add a minute.