To prepare bouquet garni, overlap the leek leaves in star pattern. Place the remaining herbs in the center, then fold over the leek leaves to create a sealed package. Tie with cooking string.
In a large pot combine wine, veggies, garlic and bouquet garni and bring to a boil. Remove from heat and set aside to cool completely.
Discard bouquet garni, pour marinade into large Ziploc and add meat. Refrigerate for 24 hours.
On Day 2, remove the meat to a plate then pour the marinade through a strainer, reserving veggies. Pour the marinade into a Dutch oven and bring to a boil, skimming off any impurities that rise to the surface. Set aside.
Season meat with salt and pepper and dredge lightly in flour. Heat oil in a large skillet then sear the meat in batches so as not to overcrowd the pan (which will cause excess moisture to be released from the meat causing it to steam instead of sear), about 2-3 minutes per side. Add meat to Dutch oven.
In skillet, add reserved marinated veggies along with a tablespoon of oil if necessary and sauté over medium-high heat until they begin to brown and caramelize, about 10 minutes. Place veggies over the meat in the Dutch oven, along with the beef and chicken stock - add more stock if needed to ensure meat is covered. Place lid on Dutch oven and bring to a boil.
Transfer to oven and bake at 275°F for 2-4 hours or until meat is tender and fully cooked (after 2 hours, check meat every 20 minutes until it is fully cooked).
Remove meat from pot, strain juices into a skillet (discarding veggies at this point) and bring to a boil. Continue to boil uncovered for about 15 minutes until a sauce with a nice consistency is created (slightly thickened). Season to taste with salt and pepper. Divide up meat into bowls and pour sauce over each.