Add chicken carcass, quartered onion, 3 roughly chopped carrots, celery top, leek greens, parsley, bay leaves, peppercorns, and stock cube to a pan
Cover with water, bring to the boil and low simmer for 3 hours
Strain, discarding the vegetables and picking any leftover scraps of meat off the bones, adding them back to the stock
Refrigerate overnight or add straight back into the pot
Add grated onion, sliced leeks, sliced celery stalks, grated carrots, and washed rice to the stock
Bring to the boil and simmer until vegetables and rice are tender
Finish with a squeeze of lemon juice and season with salt and pepper to taste
Ladle into bowls, top with black pepper and a drizzle of lemon infused olive oil
