01 -
Generously season the beef chuck roast with sea salt and black pepper on all sides. Heat olive oil in a large skillet over medium-high heat and sear the roast for 3-4 minutes per side until a deep brown crust forms. Transfer the roast to the crockpot.
02 -
Reduce heat to medium. Add unsalted butter to the skillet, then add the sliced yellow and red onions. Cook, stirring occasionally, for 10-15 minutes until onions are deeply golden and caramelized. Stir in minced garlic and cook for 1 additional minute until fragrant.
03 -
Pour dry red wine and ruby port into the skillet, scraping the bottom to lift browned bits. Allow the alcohol to reduce by half, about 3-5 minutes.
04 -
Pour the onion and wine mixture over the seared beef in the crockpot. Surround the roast with Worcestershire sauce, balsamic vinegar, beef broth, beef bouillon powder, thyme, rosemary, paprika, and bay leaf.
05 -
Cover and cook on low for 8 hours or on high for 5-6 hours until the beef is fork-tender and flavors have melded.
06 -
Remove the bay leaf and skim off any excess fat from the sauce. Slice or shred the beef and spoon generous amounts of onion sauce over each portion. Garnish with freshly chopped parsley before serving.