Cook the diced bacon or pancetta in a large saucepan over medium heat until crispy, about 5-7 minutes. Set aside on paper towels.

Sear seasoned beef chunks in the bacon grease over medium-high heat for 4-6 minutes per side until browned. Set aside.

Sauté diced onion, carrot, and celery in the same pan for 7-10 minutes until softened and onion is translucent.

Add chopped garlic and red pepper flakes, stirring for 1 minute until fragrant.

Pour in beef broth and crushed tomatoes, scraping the bottom for flavorful bits. Add cooked bacon, thyme, rosemary, and Italian seasoning. Stir and add back the beef.

For stovetop, simmer on low heat for 2-4 hours. For oven, preheat to 275°F and cook covered for the same duration. In a slow cooker, cook on LOW for 8-10 hours or HIGH for 4-6 hours.

Taste and adjust seasoning. Remove bay leaves before serving.