For the biscuits, pick and finely chop the herb leaves, then combine with the flour, baking powder and 1½ teaspoons sea salt.
Cut the butter into chunks, and work into the flour with your fingers until the mixture forms big crumbs, the size of small peas.
Add the cream and mix until evenly incorporated and slightly sticky.
Turn out onto a lightly flour-dusted board and pat into a 2.5cm-thick circle. Using a 5cm-diameter cutter, cut into 12 to 14 rounds.
Trim and finely chop the celery, then peel and finely chop the onion. Peel the squash, then cut into 2.5cm pieces along with the carrots.
Heat 1 tablespoon of oil in a large saucepan over a medium heat, and add the celery and onion. Cook for 4 to 5 minutes, until the vegetables start to turn golden, stirring often.
Add the carrots and squash and sauté until they begin to soften.
Add the bay leaf and chicken stock, bring to the boil, then reduce to a simmer for 20 minutes, or until the vegetables are tender.
Preheat the oven to 190ºC/gas 5.
In a bowl, whisk 120ml of cold water with the flour until combined. Add a cup of the hot broth to the mixture and whisk well. Strain the mixture and whisk it back into the broth.
Bring the broth to the boil. Shred or dice the chicken, add to the pan and season with sea salt and black pepper. Reduce the heat and simmer for 5 minutes.
Pour the broth into a 2.8-litre baking dish. Top the chicken with the uncooked biscuits and bake for 35 to 40 minutes, or until the biscuits are golden and cooked through, and the broth is bubbling. Serve straightaway.
If low on meat you can always cook up a little extra. The scone-like biscuits sit on top, like dumplings, and soak up the broth nicely. To make the biscuits on their own, bake them in a preheated oven at 220ºC/gas 7 after step 2.