To begin, soak the almonds in cold water for 24 hours

To make the pasta dough, mix all the ingredients in a stand mixer using a dough hook. Wrap the dough in cling film (or vacuum seal if you have sous vide equipment) and rest in the fridge for 30 minutes

Blitz the soaked almonds in a high-power blender until smooth, or use a Pacojet to process if you have one. Whip the 'nduja, pass through a sieve and mix with the almond mixture in a bowl. Transfer the mixture to a piping bag

Roll out the pasta dough to make two 2mm thick sheets. Pipe blobs of the 'nduja onto the first pasta sheet, then carefully cover with the second sheet. Using a little water to seal, gently but firmly press down around each mound of filling to ensure a good seal. Cut out the ravioli using a very small pastry cutter or ravioli stamp. Store the bottoni under a slightly damp cloth in the fridge to prevent them from drying out

Preheat the oven to 180°C/gas mark 4

For the broth, salt the potato peelings then roast in the oven for 30 minutes. Transfer to a pressure cooker with 4l of water and a splash of white wine and cook for 40 minutes

Safely release the pressure and strain the broth through a fine sieve. Taste and adjust the seasoning with salt

When ready to serve, cook the pasta in salted boiling water for 1 minute

Divide the bottoni between bowls and pour in the broth. Garnish with fennel fronds and serve