Heat the olive oil in a skillet or pot over medium-high heat.
Once the oil is hot, add the beef chuck roast to the pot and cook until browned on all sides, about 5 minutes per side.
Remove the beef from the pot and transfer it to the slow cooker.
In the same pot, add the vegetables (chopped onion, minced garlic, chopped celery, and chopped carrots). Cook until the vegetables are soft, about 8 minutes.
Add tomato paste and stir until well mixed, about 2 minutes.
Add the red wine, beef broth, brown sugar, dried thyme, and bay leaves to the pot. Stir until all ingredients are well combined.
Pour the mixture over the beef in the slow cooker.
Cover the slow cooker and cook on low for 8 hours or on high for 4 hours.
Once the beef is tender and falling apart, remove it from the slow cooker and transfer it to a serving platter.
Pour liquid into a pot (with vegetables strained if desired) and bring to a simmer, stirring occasionally, until sauce is reduced/thickened. Add salt and pepper to taste.
Pour the reduction sauce over the beef and serve hot.