Put vegetables and bouquet garni on bottom of a 10 quart stock-pot and chicken parts on top. Add water, just enough to cover chicken and slowly bring to a simmer. Turn heat down to keep broth at a slow simmer and cook for 3 hours, skimming off froth and fat that surfaces in the first 30 minutes. Also be sure to replace evaporated water.
Strain stock into a clean saucepot. Cool uncovered and refrigerate. The next day, spoon off any discarded congealed fat from surface.