In a large oven-safe saucepan, cook diced bacon until crispy and golden brown. Remove and set aside, leaving fat in the pan.

Season the beef with salt and pepper. Sear in the bacon grease until browned on all sides, about 4-6 minutes each side. Set beef aside.

Add diced onion, carrot, and celery to the pan. Sauté on medium heat until tender, about 7-10 minutes.

Stir in minced garlic and red pepper flakes. Cook for 1 minute until fragrant.

Pour in beef broth and crushed tomatoes, add thyme, rosemary, bay leaves and reserved bacon. Stir well to combine.

Return beef to the pan, bring to a gentle boil, covering the dish. Cook on the stove, in the oven, or in a slow cooker as desired.

Check the beef for tenderness after cooking; it should easily shred with a fork. Adjust seasoning before serving, and remove bay leaves.