Season the Beef: Start by seasoning the beef chuck roast with salt and pepper.
Sear the Beef: In a large skillet over medium-high heat, add the olive oil. Once hot, sear the beef cubes in batches, turning until browned, about 5-7 minutes. Transfer to the slow cooker.
Sauté the Onion: In the same skillet, add the chopped onion. Sauté for about 5 minutes until softened.
Add Garlic: Toss in the minced garlic and cook for an additional minute until fragrant.
Combine in Slow Cooker: Transfer the sautéed onion and garlic to the slow cooker over the beef.
Mix the Gravy Ingredients: Stir in the crushed tomatoes, beef broth, tomato paste, Worcestershire sauce, oregano, and basil. Mix well.
Slow Cook the Beef: Cover and cook on low for 6–8 hours or high for 3–4 hours.
Taste and Adjust: Before serving, taste the gravy and adjust seasoning with salt and pepper.
Serve and Enjoy: Serve over rice, mashed potatoes, or pasta. Garnish with fresh parsley if desired.