Step 1: Marinate the Beef
Place beef cubes in a large bowl. Add red wine, garlic, bay leaves, thyme, salt, and pepper. Cover and refrigerate for at least 8 hours or overnight to infuse the meat with flavor and tenderness.

Step 2: Prepare and Brown the Meat
Drain the beef, reserving the marinade. Pat the beef dry with paper towels. In a skillet, cook bacon until crispy, then transfer to the slow cooker. Add half the olive oil to the same pan and brown the beef in batches. Transfer to the slow cooker.

Step 3: Sauté the Vegetables
In the same skillet, heat the remaining olive oil. Add carrots and onion, sauté until golden (about 5 minutes). Sprinkle in flour and stir for 1 minute. Slowly pour in the reserved marinade, scraping any brown bits from the pan. Add beef broth, tomato paste, sugar, and Worcestershire sauce. Stir well and pour into the slow cooker.

Step 4: Slow Cook to Perfection
Add mushrooms and pearl onions to the slow cooker. Stir gently. Cover and cook on low for 8–9 hours or high for 4–5 hours, until beef is fork-tender and sauce thickens. If the sauce is too thin, leave the lid slightly ajar for the last hour.

Step 5: Finish and Serve
Taste and adjust seasoning. Remove bay leaves and thyme sprig. Garnish with chopped parsley before serving.