Season the beef chuck roast on all sides with sea salt and black pepper.
Heat the ghee in a heavy-bottomed pot or Dutch oven over medium-high heat.
Sear the beef for 3-4 minutes per side until a deep brown crust forms, then remove the beef and set aside.
Add the minced garlic to the pot and sauté for 30 seconds until fragrant.
Pour in the beef broth and coconut aminos, scraping the bottom of the pot to release the flavorful browned bits.
Return the beef to the pot, cover with a tight-fitting lid, and reduce heat to low.
Simmer for 2.5 to 3 hours, or until the beef is tender and shreds easily with a fork.
While the beef cooks, peel and chop the potato, then boil in salted water until soft.
Drain the potato and mash thoroughly with the grass-fed butter until smooth and creamy.
Shred the beef into large chunks and serve in a bowl over the mashed potatoes, drizzling the remaining pan juices over the top.