Splash of olive oil
1 onion, finely diced
1 celery stalk, finely diced
50g plain flour
2 tbsp dijon mustard
Good pinch of smoked sweet paprika
Good pinch of freshly grated nutmeg
A few small splashes of Tabasco sauce
250g cheddar or Gruyère cheese, grated
40g parmesan, grated
200g good-quality ham off the bone, cut into 1.5cm cubes, or pre-sliced ham, roughly chopped
3 tbsp olive oil
100g fresh breadcrumbs
90g walnuts, finely chopped
1 garlic clove, finely chopped
4 flat-leaf parsley sprigs, finely chopped
Zest of 1 lemon
Salt flakes and freshly ground black pepper
For the topping, heat the oil in a frying pan over medium heat. Add the breadcrumbs and toss frequently in the pan until they are a light golden colour, 5–10 minutes. Sprinkle in the walnuts and toss again for five minutes until the crumb mix is golden brown and very crunchy. Remove from the heat and cool slightly, then add the garlic, parsley and lemon zest and mix through the crumb. Season with salt and pepper and reserve.
Combine 20g of butter, the oil, onion and celery in another large saucepan over medium heat and sweat, stirring regularly, for 10 minutes until the onion and celery are soft.
While the vegetables are cooking, bring a large saucepan of salted water to the boil. Add the pasta and cook as per the packet instructions. (I like to undercook mine by 2 minutes to ensure the pasta is al dente.) Drain well.
To finish the sauce, add the remaining butter to the onion mixture and allow it to melt, then, with a wooden spoon, stir in the flour to make a roux. Continue to stir for 2–3 minutes to cook out the raw flour taste. Remove from the heat and, to prevent lumps, vigorously whisk in a quarter of the milk. Place back on the heat, add the rest of the milk and whisk until the sauce comes to the boil and thickens. Take off the heat and mix in the mustard, spices, Tabasco and cheeses.
Fold the pasta into the sauce, coating the noodles well, then fold in the ham. Pour onto a serving platter or portion into separate bowls and sprinkle on the topping. Serve with a crisp green salad.