Place lamb on a plate and pat dry with clean paper towel.
Season all over with kosher salt and ground black pepper.
Bring Dutch Oven to medium-high heat. Sear lamb on all sides. Remove and set aside on a plate.
Add butter and let melt.
Add garlic and move around pan until fragrant, approx. 30 seconds.
Add celery, carrots and onion. Add 1 teaspoon kosher salt and 1/4 teaspoon ground black pepper. Move around pan (add additional tablespoon of butter if pan seems dry) until the onions soften slightly, approx. 2-3 minutes.
Add red wine and marinara sauce, stir to combine.
Add lamb back into the pot along with any settled juices. Try to submerge the lamb as best as possible.
Nestle your herb bundle inside the pot as well.
Cover and let simmer on the stove top 3-4 hours (alternatively you can place it in a 325 degree oven).
Remove lamb and shred meat. Return meat to the pot and discard any bones.
Stir to combine.
Serve over your choice of gnocchi, pasta, zoodles, etc.
Notes
Make it creamy: feel free to add in a 1/4-1/2 cup heavy cream OR a dairy-free equivalent (dairy-free heavy cream or full fat coconut milk).
Slow Cooker/Crock Pot: follow directions through Step 6. Add sautéed ingredients to slow cooker along with red wine, marinara, herb bundle and seared lamb. Stir to combine. Cover and let cook on LOW 6-8 hours or on HIGH 3-4 hours. Following remaining instructions.
Pressure Cooker/Instant Pot: follow directions through Step 6. Add sautéed ingredients to pressure cooker along with red wine, marinara, herb bundle and seared lamb (Note you are definitely free to just do all the steps in the pressure cooker using the sauté function). Stir to combine. Cover and ensure pressure cooker is set to Seal. Cook on High for 50 minutes. Naturally release pressure for 10 minutes. Following remaining instructions.
Storage: Store leftovers in an airtight container in the refrigerator for up to 3 days.
Freezing: let cool completely then transfer to an airtight, freezer-safe container. Label and place in the freezer. Use within 6 months. Place in the refrigerator to thaw overnight before use.
Red Wine Sub: feel free to use pomegranate juice instead of red wine.
Whole30: to make this Whole30/Paleo simply use pomegranate juice instead of red wine and ghee instead of butter.