Blue Cheese Mac and Cheese (Sharp, Grown Up, Never Bitter)

Ingredients

• 350g dried macaroni, rigatoni or conchiglie
• 2 medium leeks, halved lengthways and finely sliced
• 1 tbsp olive oil
• 50g unsalted butter
• 50g plain flour
• 600ml whole milk
• 100ml double cream
• 1 bay leaf
• 1 tsp Dijon mustard
• A few gratings of fresh nutmeg
• 150g Stilton or Gorgonzola Piccante, at room temperature, crumbled
• 150g Fontina, coarsely grated (young Gouda or Emmental also work)
• 60g walnut halves, roughly chopped
• 50g panko or coarse sourdough breadcrumbs
• 1 tbsp thyme leaves
• 15g unsalted butter, melted, for the crumb
• Plenty of black pepper, salt only at the very end

Instructions

1. Take the blue cheese out of the fridge at least 20 minutes before you start and crumble it into a bowl. Room temperature cheese melts off the heat, which is the whole trick.
2. Heat the oven to 200C, 180C fan. Warm the olive oil in a wide pan over a low heat, add the sliced leeks and a pinch of salt, and cook gently for 10 to 12 minutes until soft and sweet but not coloured. Set aside.
3. Bring a large pan of well salted water to the boil and cook the pasta for 2 minutes less than the packet says. It will finish cooking in the oven. Scoop out a mugful of the starchy cooking water, then drain.
4. Melt the 50g of butter in a heavy saucepan over a medium heat. Stir in the flour and cook for 2 minutes, stirring constantly, until it smells biscuity rather than raw.
5. Add the milk a splash at a time, whisking hard after each addition so no lumps form. Add the cream and the bay leaf, bring to a gentle simmer and cook for 5 minutes, stirring, until it coats the back of a spoon. Fish out the bay leaf.
6. Take the pan off the heat. This is the important step. Let it sit for a minute so it stops bubbling, then stir in the Fontina until smooth, followed by half the crumbled blue cheese, the Dijon and the nutmeg. Do not put the pan back on the hob.
7. Taste. It should be sharp and savoury. Add black pepper generously and salt only if it genuinely needs it, because the blue is already salty.
8. Stir the drained pasta and the softened leeks into the sauce, loosening with a little pasta water if it feels tight. Tip half into a 2 litre baking dish, scatter over the remaining crumbled blue, then add the rest of the pasta.
9. Mix the breadcrumbs, walnuts, thyme and melted butter together and scatter evenly over the top so the surface is fully covered. The crumb protects the blue cheese underneath from direct heat.
10. Bake for 20 to 25 minutes until the crumb is deep golden and the sauce is bubbling at the edges. If you want more colour, give it 2 minutes under a hot grill, watching it constantly.
11. Rest for 5 minutes before serving. Eat with a sharply dressed green salad.

Blue cheese mac and cheese lives or dies on one thing, and it is not the pasta.

The rule that matters: never add blue cheese to a pan that is still on the heat. Build the sauce, take it off the hob, wait until it stops bubbling, then stir in room temperature crumbled blue. Blue cheese that gets boiled turns bitter and grainy, and no amount of cream will bring it back.

That single bit of technique is the difference between a sauce that tastes like a proper cheese course and one that tastes like a mistake.

This is not the three cheese mac with blue thrown in

If you want the golden, comforting, everybody-loves-it version, go and make the ultimate three cheese mac and cheese. It is the better Tuesday dinner.

This one is deliberately grown up. Sharper, saltier, more savoury, with only two cheeses in the sauce, sweet softened leeks underneath and a walnut and thyme crumb on top. It wants a green salad and a glass of something red. Most children will hate it. That is rather the point.

Which blue cheese to use

Pick one of these three.

Stilton is the safest choice. It is a PDO cheese, made only in Derbyshire, Leicestershire and Nottinghamshire from pasteurised cow's milk, and it is firm, crumbly and meaty rather than screamingly salty. Depth without a takeover.

Gorgonzola Piccante is the sharp option. It is the aged, firmer style of Italian gorgonzola and it pushes the sauce right to the edge, in a good way. Use a little less than you would Stilton.

Gorgonzola Dolce is the gentle option. Young, soft, almost spreadable, and it melts more smoothly than anything else here. Good for people who claim not to like blue cheese.

What to avoid: Roquefort is magnificent, but it is sheep's milk and very salty, and 150g of it in a bechamel bullies everything else. Cheap blue cheese sold in a plastic tub is usually oversalted and thin, and it is the main reason people think they hate this dish. For where these cheeses came from, we covered the history of blue cheese separately.

The mellow cheese that keeps it civil

Blue cheese on its own does not make a good sauce. It has the flavour but not the melt. You need a second cheese that is buttery, stretchy and quiet.

Fontina is the best of them: Italian, cow's milk, semi soft, and it melts into a genuinely silky sauce without adding much flavour of its own. Young Gouda does a similar job and is easier to find. Emmental works. Taleggio works if you want it funkier. Do not reach for mature Cheddar, because it competes with the blue for the same space and everything ends up muddled. Have a look through the cheese catalogue if you want to check what else melts cleanly.

Five rules for blue cheese that never goes bitter or grainy

1. Take the pan off the heat first. Blue cheese melts happily at around 60 to 70C, which a finished bechamel already is. Extra heat is exactly what makes the proteins tighten and squeeze the fat out into greasy little beads.
2. Never let the sauce boil again once the cheese is in. If it needs loosening, use hot milk or starchy pasta water, not the hob.
3. Bring the cheese to room temperature and crumble it small. Fridge-cold lumps sit there refusing to melt, which tempts you to turn the heat back on. Twenty minutes on the counter fixes it.
4. Keep a starch in the sauce. A proper flour based roux is not optional here. Starch holds the fat and the protein politely together. If it still looks split, whisk in a teaspoon of cornflour slaked in cold milk.
5. Hold back half the blue and add it as pockets. Stir half into the sauce and scatter the rest through the pasta as you assemble. You get bursts of blue instead of one relentless note, and less of the cheese gets cooked twice.

A sixth, quieter rule: bitterness is knocked back by fat and a little sweetness, which is exactly why there is cream, softened leeks and Dijon in this recipe.

The crumb is not decoration

Blue cheese sitting directly under a grill element goes acrid fast, so the walnut crumb works as a lid. It is also one of the oldest reliable pairings there is, and ten minutes in a hot oven wakes the nuts up.

Make it ahead

Assemble it, cool it, cover it and refrigerate for up to two days. Add the crumb just before baking and give it an extra ten minutes. Do not freeze it, because the sauce separates on defrosting.

Quick answers

Can I use Roquefort or Danish Blue? Yes, but halve the quantity and make the difference up with more Fontina. Both are noticeably saltier than Stilton.

Why did my sauce go grainy anyway? Almost always heat. Either it was still simmering when the cheese went in, or it went back on the hob afterwards.

What pasta is best? Macaroni is traditional, but rigatoni or conchiglie trap more sauce and give better pockets of blue.

What should I drink with it? Something with grip. A Cotes du Rhone, a dry cider, or a stout.

Log the blue you used in Cheezus so you know exactly which one to buy again next time.