Place the meats and bones in a very large pot and cover with cold water: Beef Shank, Beef Chuck, Beef Brisket and Marrow Bones with enough Water to cover by 1–2 inches. Slowly bring to a gentle simmer over medium heat.
As the water heats, skim off any foam or impurities that rise to the surface so the broth stays clear. Once simmering, reduce heat to low so the liquid barely bubbles.
Prepare the aromatics: halve an Onion and stud each half with a few Cloves; add the onion, a Bouquet Garni, a generous teaspoon or two of Black Peppercorns, and a pinch of Coarse Sea Salt to the pot. Continue to simmer very gently, uncovered, for about 2–3 hours, until the meats are tender and the broth is richly flavored.
While the broth cooks, prepare the vegetables: peel and cut the Carrots into large chunks, trim and wash the Leeks and slice into large pieces, cut the Celery into long stalks, and halve or quarter the Turnips. Cut the Potatoes into large chunks but keep them aside until later.
About 45–60 minutes before serving, add the carrots, leeks, celery and turnips to the pot so they cook through but retain shape (timing can be adjusted to preference). Add the Potatoes in the last 20–30 minutes so they become tender without falling apart.
When everything is tender, carefully remove the meats and bones to a cutting board or platter and strain the broth through a fine sieve into a clean pot or bowl; skim off excess fat if you prefer a leaner consommé. If you like marrow, split the Marrow Bones and scoop the marrow to serve alongside the meat.
Slice the meats against the grain and arrange them with the cooked vegetables on a large platter. Warm the strained broth and serve it in bowls as a clear soup course or ladled at the table.
Serve the platter with mustards and pickles—Dijon Mustard and Cornichons—and plenty of rustic Country Bread for dipping. Finish at the table with extra Coarse Sea Salt and freshly ground pepper to taste.
