Heat a large skillet over medium-high heat. Once the pan is hot, add the bacon. Cook the bacon until crispy and then transfer to a paper towel lined plate.
Meanwhile, season the beef cubes well with salt and pepper.
In one layer (careful not to crowd), add beef cubes. Sear for 1-3 minutes, then flip, and sear another 1-3 minutes or until seared on all sides. Transfer to the slow cooker and repeat with the remaining beef, working in batches until all the meat is seared and placed into the slow cooker.
Add the bacon, onion, celery, garlic, and mushrooms to the slow cooker. Tuck the sprigs of thyme and the bay leaves in between the vegetable-meat mixture. Add the broth and wine— the liquid should almost completely cover the mixture (about ¾ of the way), so add more as needed.
Cover the slow cooker and cook on high for 4 hours. After 4 hours, add the carrot noodles quickly and then cover. Cook for another 1 hour or until beef is tender and pulls apart.
When done, give everything a big stir to combine and remove the bay leaves. Serve in bowls and garnish with parsley and red pepper flakes, if desired.
Adapting classical French braising techniques for a basin-style slow cooker requires accounting for moisture retention, since a tight ceramic lid prevents the evaporative reduction that traditionally concentrates Pinot Noir and beef stock over three hours at 300 degrees Fahrenheit. Substituting chuck roast with leaner round cuts demands careful attention, as lack of intramuscular fat leads to dry fibers unless the cooking liquid covers at least three-quarters of the meat mass. Rendering five slices of thick-cut bacon first builds the necessary lipid foundation for searing the beef cubes in batches for one to three minutes per side, creating the Maillard reactions essential for deep flavor development without burning the minced garlic.
Introducing spiralized yellow onion and carrots during the final hour of the four-hour high-heat cycle prevents the vegetables from dissolving into mush, preserving structural integrity while absorbing the rich red wine broth. Removing the woody thyme sprigs and bay leaves before serving ensures a clean palate, while fresh parsley and optional red pepper flakes cut through the heavy protein richness. Understanding how moisture, fat ratios, and timing interact prevents the dish from turning into an unctuous stew.