First we brown the butter and toast the walnuts. Place 125-130g of butter in a saucepan over medium heat. Let it melt completely, then continue cooking, swirling the pan occasionally. The butter will foam, then the foam will subside, and you’ll start to see golden brown bits forming at the bottom. It should be ‘iced tea’ colour. Once it’s golden brown, immediately pour it into a heatproof bowl to stop the cooking. You should have about 110g of brown butter once the water has evaporated. Let it cool to room temperature before using.

Whilst the butter is cooling, toast your walnuts. Spread them on a baking tray and toast in a preheated oven at 160°C for about 10-16 minutes, or toast them in a dry frying pan over medium heat for 5-7 minutes, stirring frequently. Let them cool, then chop them roughly. Set aside. Toasting the walnuts is essential.

Oven to 160°C. Line a large baking tray with baking parchment. In a large mixing bowl, whisk together the eggs and sugar until slightly pale. This takes about 2-3 minutes by hand. Add the cooled brown butter and whisk until smooth and glossy.

In a separate bowl, whisk together the flour, baking powder, and the salt. Add the dry ingredients to the wet mixture and fold together gently with a spatula until about halfway combined. You should still see streaks of flour. Add the cheeses and toasted walnuts. Fold everything together until just combined. The dough will be quite soft and slightly sticky, which is right. Place the dough in the fridge for 2h.

Take the dough out off the fridge and let come to room temp, or 15 mins is fine too. Turn the dough out onto a lightly floured surface. Divide it in half. Shape each half into a long log, about 25-30cm long and 5-6cm wide. The logs should be slightly flattened on top, not perfectly round. Carefully transfer the logs to your prepared baking tray, leaving plenty of space between them as they’ll spread. Bake for 25 minutes, or until the logs are slightly cracked on top.

Remove from the oven and let them cool on the tray for about 5 minutes. Using a big sharp knife or a bench scraper (even better and easier with it), carefully but in quick and harshly movements cut each log into pieces about 1.5cm thick, 10-12 slices from each log. They can be quite close together as they won’t spread during the second bake. Return to the oven and bake for another 15 minutes, or until the biscotti are deeper in colour. They’ll still feel slightly soft when you take them out, but they’ll harden as they cool.

Let them cool for at least 10mins. However when they cool completely, they will be properly crunchy. Serve immediately. Let them cool completely before storing. They keep for up to 2 weeks in an airtight tin, even 3 weeks. They actually improve slightly after a day or two as the flavours develop. Serve with coffee, tea, wine, or just eat them on their own dipped in some greek yogurt or sour cream.