In a big pot, put the meat, the hole onion, and cover with water. Bring to a boil, skim the foam and leave to stew for 1 hour at low heat.
In another pot, put the lentils, the diced carrots, a half onion cut in big pieces, and the bouquet garni. Add salt, pepper and cover with water. Bring to a boil and leave 25 minutes at medium heat.
Once it all has cooked, take one laddle of the meat water. Then strain the meat and the onion.
Strain also the lentils and take the bouquet garni out. Put the meat and the lentils in a big pot, add the laddle of water and stir.
Cook 25 minutes at medium/low heat
There you are, your pork butt with lentils is ready!
= 
