Boil a kettle and add boiling water to a pot on medium-high heat. Salt the water as preferred (I use half a tablespoon of salt for a medium pot) then add the pasta and cook as per instructions. You want to drain it while it's still al dente so remove from heat 2 minutes before the recommended cooking time. I used Gragnano pasta in the "spaghettini" cut, which cooks in 8 mins so I removed it from the heat after 6 mins and removed the excess water using a sieve (you can use a colander as well).

While the pasta is cooking, heat up the knob of butter in a pan and add the chopped walnuts once it's hot. Toast them until they become golden brown, then add the drained pasta. Stir well.

Add the juice of half a lime and grind some black pepper on top (to taste). Add the bottarga and stir well for a minute or so.

Spoon some truffle pesto on a serving plate and place the pasta on it. Top with some more bottarga and walnuts. Serve hot - no one likes limp pasta!!