Place <quantity>500<unit>g</unit></quantity> of chopped pig trotters and <quantity>500<unit>g</unit></quantity> of chicken feet on a roasting pan

Broil it on maximum temperature until well roasted

Chop <quantity>2</quantity> celery stalks

Chop the white part from <quantity>1</quantity> leek, discarding the root. Keep the green part for later use

Trim and chop <quantity>1</quantity> large carrot

Trim, peel, and chop <quantity>1</quantity> onion

Transfer the chopped vegetables to a roasting pan and broil on maximum temperature until toasted

Use a leek leaf to tie together <quantity>1<unit>sprig</unit></quantity> of rosemary, <quantity>1<unit>sprig</unit></quantity> of thyme, and <quantity>2</quantity> bay leaves

Transfer the roasted meats and vegetables to a large pot and add the tied herbs

Fill the pot with water enough to cover all the ingredients. Bring it to a boil over low heat and cook for 4h to extract the flavors

Strain it through a fine mesh sieve. The chicken feet stock is ready

Reduce <quantity>2<unit>L</unit></quantity> of the Chicken Feet Stock in a saucepan over medium heat to ⅓ of the initial volume

Add <quantity>50<unit>g</unit></quantity> of cold butter. Turn off the heat and let it melt, stirring until combined

Add ground black pepper to taste and stir to combine

Add the remaining <quantity>25<unit>g</unit></quantity> of butter and stir to combine. The chicken demi-glace is ready

Enjoy this rich and velvety sauce!