Double cream, cheese, english mustard, done.
That's not a recipe, that's just a list of random words.
How about giving him some quantities along with a method and any ingredient specifics?
Alternatively, SideWinder could try this sauce.
Ingredients:
20g unsalted butter.
20g plain flour.
300ml milk.
125g grated cheddar/assorted cheeses
25g grated parmesan.
1 tsp English mustard (optional)
Method:
1. Melt the butter in a saucepan over a medium heat until it is just starting to bubble. Add the flour and quickly stir (or whisk) to form a roux, making sure to incorporate all the flour into the melted butter.
2. Continue stirring/whisking for 5 minutes until the flour has cooked out and the colour of the mixture has darkened slightly. You should be able to feel the 'grainy' texture of the mixture dissipate as it cooks.
3. Slowly add the milk, ensuring you stir/whisk all the time. Be careful when initially adding the milk in as the roux will instantly thicken and you can ruin things at this stage. Be careful, go slow and keep the mixture moving as you slowly add the rest of the milk.
4. Cook for 10-15 minutes until you have a thickened yet smooth and flowing sauce. Remove from the heat and slowly add the grated cheese whilst stirring continuously, then add the mustard (if using).
5. Once all the cheese has been incorporated check the seasoning and adjust as necessary. Then return the pan to the heat and bring the sauce up to your desired temperature.
6. Finally, add your cooked pasta to the sauce or vice-versa. Serve immediately.