Cut the roast beef (shoulder) and bacon into large cubes. Season with sea salt and pepper. Clean the chanterelles, young carrots, and spring onions, and cut them into large pieces.
Heat the butter in a saucepan over medium-high heat. Working in batches, fry the bacon and beef for 3-4 minutes per batch until lightly browned. Add the vegetables and sauté for 2-3 minutes. Sprinkle with flour and stir to coat.
Deglaze the pan with the cognac. Add the red wine (Burgundy) and the peeled, chopped garlic. Reduce heat to medium and simmer for 2 hours 30 minutes until the beef is tender.