Classic Slow Cooker Pot Roast

1 (3-pound) chuck roast, trimmed of excess fat

Sea salt and freshly ground pepper,

1 tablespoon ghee

1 onion, cut into wedges

1 sweet potato, peeled and cut into large wedges

4 carrots, cut into large chunks

4 cloves garlic, peeled

Small handful thyme sprigs

3 sprigs rosemary

1 tablespoon tomato paste

1 1/2 cups beef bone broth

1 tablespoon apple cider vinegar