Roughly chop the carrots, leek, celery, or celeriac. Place them into a pot together with 2 of the garlic cloves and the whole chicken breasts.

Cover with the water, bring to a boil, turn the heat down and simmer uncovered for 10 minutes. Remove the chicken breasts from the pot and set them aside.

Continue cooking the stock (uncovered) while you prepare the rest. You will need some of the stock for the recipe. (Note 1 and 2)

Remove the seeds from the yellow peppers and quarter them. Place them into another pot, cover with water, bring to a boil, turn the heat down and cook for about 10 - 15 minutes or until soft. Drain well.

Return the peppers to the pot, add about 60 ml/ ¼ cup from the cooking chicken stock and the remaining 2 garlic cloves. Puree until smooth. Set aside.

Place the torn white bread slices and the walnuts in a bowl. Add 60 ml/ ¼ cup of the cooking chicken broth. Puree the toast and the walnuts to obtain a thick paste. Set aside.

Chop the onion and the chili finely. Heat the oil in a Dutch oven or another heavy-bottomed pot and cook the onion until translucent. Add chili, pepper sauce, and ¼ cup of the chicken broth. Turn the heat down to low and simmer for about 15 minutes or until slightly thickened.

Add the bread - walnut mixture. Stir well and simmer for 5 minutes more. If the sauce is not smooth enough at this point you can blend it again.

In the meantime shred the cooked chicken breasts. Add the chicken to the pot together with the olives. Add the milk, turn the heat a bit up and continue cooking for several minutes or until the sauce is thickened to your liking.

Adjust the taste with salt and pepper. Be generous.

Serve with hard-boiled eggs, cooked rice, and boiled potatoes.

Aji de gallina can be easily reheated. If you have leftover rice and potatoes (sliced) as well, add them to the sauce and reheat everything together. You might want to add a small amount of chicken stock or water when you reheat the sauce together with the rice and/or potatoes.