Remove chicken from any packaging and rinse in a sink with running cold water. Place chicken into a large soup pot with a fitted lid.
Pour water measure over the chicken. Turn stovetop heat to high and bring to a boil.
While the water temperature rises:• Add the peppercorns and bay leaves to the pot. • Roughly chop 2 of the carrots and 2 of the celery ribs and add to the pot. • Slice the green leaves off the leek and add around one cup of sliced leaves to the pot. • Leaving the skin on the garlic, slice off a few millimetres from the end of each clove, crush each clove flat with the back of a kitchen knife, and add each to the pot.
As the water temperature rises, a white foam will start to rise to the surface. Scoop the foam off with a spoon and discard.
Once water is boiling reduce to a simmer (this is a medium-low heat, with some gentle bubbling). Cover with lid and leave to cook for an hour minimum (or longer if you have time! Another half an hour would be great). Rotate the chook (turn over) once during the cooking time.
While the soup is cooking prepare the other vegetables. Finely slice the white part of the leek. Slice remaining carrots in half lengthways, then half again lengthways. Slice into small chunks. Slice remaining celery ribs in half, then slice into small chunks.
Once the stock is done cooking, remove chicken carefully and place into a baking dish. Keep aside.
Strain stock through a fine-mesh sieve into another pot. Discard vegetables, peppercorns and bay leaves.
In the original soup pot drizzle a little olive oil and turn the heat to a medium. Add leeks and cook for five minutes. Add carrots and celery and cook for another few minutes.
Pour stock back into pot. Bring to boil.
Once boiling, reduce to a medium heat and add noodles. Cook for five minutes, stirring once.
As the noodles cook, remove chicken meat of the carcass and shred into smaller pieces.
Add peas, baby spinach (finely slice leafy greens if using another variety), parsley and shredded chicken meat to the pot. Mix and then leave to cook for a few minutes.
Now it's time to season! It may surprise you with how much salt you need. I start with 1 Tbsp, then mix and taste, adding a tsp thereafter until it tastes right to my tastebuds (I usually end with around 2 Tbsp, but this can vary!). Add a few turns of the pepper shaker too. As an optional add on: if you'd like to boost the flavour of the stock, feel free to add chicken or vegetable stock powder to taste (keep in mind this is salty itself, so don't over do it! My pick for stock powder is the globally popular Vegeta).