Tie the herbs into a bouquet garni. Place with the whole chicken into a large deep pan and fill with enough cold water to cover the chicken.
Slowly bring to the boil, then turn it down to a simmer. Skim the froth from the surface every so often.
Allow it to bubble away for 1 hour 30 minutes, or until the chicken is delicious, soft and starting to come away from the bone.
To make the tortellini, add the pasta flour and eggs to a food processor along with a little sea salt. Blitz until everything comes together into a dough. If its too dry, add a splash of stock or water.
Tip the dough onto a floured surface and knead for a few minutes. Wrap in clingfilm and allow to rest until you are ready for it.
Carefully remove the chicken from the broth. Pull the meat from the chicken. Carefully take the breasts from the bird – they will come away very easily – and put to one side. Pull all of the remaining meat from the carcass and shred it for your pasta filling.
Add to a bowl. Pick, chop and add the tarragon (saving some of the leaves for later) along with a generous grating of Parmesan. Season with salt and black pepper, and allow to cool.
Return the broth to the heat and bring it to the boil. Trim, roughly chop and add the carrots and fennel, then simmer for 15 minutes.
Divide the dough into 6 pieces. Lightly dust a tray with flour.
Use a pasta machine (or floured rolling pin) to roll out 1 piece (covering the rest with clingfilm or a tea towel) into a long, very thin 10cm-wide strip. Slice into 5cm squares.
Place 1 teaspoon of the chicken filling in the middle of a pasta square, then fold the pasta into a triangle, pressing the edges to seal.
Wind the folded edge around the tip of your middle finger and press the ends to form a ring. Place on the floured tray.
Continue until you have used all the rolled-out dough, then repeat with the rest of the dough.
Get the broth to a rolling boil and add the peas and broad beans, and the chicken breasts. Chop the asparagus into 1cm pieces and add those too, followed by your tortellini. You will know when they are done because after a few minutes the tortellini will float to the surface.
Divide the carrot and fennel between the serving bowls. Use two forks to shred the chicken breasts and share the meat between the bowls, along with the tortellini, peas and beans.
Ladle over the broth and serve topped with tarragon leaves and fine gratings of Parmesan.