cover the oven tray with aluminum foil
place the chicken onto the tray
add a bit of olive oil onto the chicken
place the tray in the oven's middle rack at 180℃-356℉
let it roast until it's nice and gold
flip it along the way so that you get it golden on all sides
wash your veggies thoroughly, cut off the ends and then chop them roughly, don't take off the leaves when you're making a stock because that gives a lot of flavor
place them in a bowl
once the chicken is brown on all sides transfer them in a large pot along with the vegetables
add thyme
cover it with water
add about 40 black pepper corns
place the lid on and bring it up to a boil
once it starts boiling transfer the pot to a small burner to slow simmer
after 2 hours check if there is any scum on top so you can skim it off
let it simmer for three four more hours
switch it off and let it cool a bit so you can clean off the stock
take out all of the solids with your spider strainer and put it into a bowl
strain it into smaller bowls so it's easier to handle and then freeze it