Mix together 1 cup of vinegar and 2 cups of water in a large bowl. Add cow heel to water and vinegar mixture and let steep for 30 minutes. Then drain and rinse with clean water.
Season mixed beef with 1/2 tablespoon garlic powder, 1/2 tablespoon onion powder, 1 teaspoon of salt, 1/4 teaspoon cayenne pepper, 1/4 teaspoon black pepper and set aside.
Set your instant pot to Sauté. When hot add oil to instant pot.
When oil is hot add seasoned mixed beef and saute for 3 to 5 minutes until the beef is brown on all sides
Remove beef from the instant pot and set aside
Add cow heel to the instant pot, followed by the remaining seasoning (except for the cinnamon, cloves, orange peel and pepper), all the sugar and 1/2 of the cassareep and 5 cups of water.
Mix together until sugar dissolves. Then cover the instant pot and pressure cook on high for 1 hour.
After an hour, release the pressure (vent the Instant pot following the instructions for venting in the manual), and check cow heel for tenderness.
Add sautéed beef and the remaining cassareep to the instant pot.
Add your cinnamon stick and cloves to the cotton fabric and tie together (as demonstrated in the video above). Then add to the instant pot, mix together well, then pressure cook for another 45 minutes.
Vent the Instant pot following the instructions for venting in the manual, then check the beef and cow heel for tenderness.
Finally, add the pepper and orange peel then pressure cook for an additional 30 minutes.
Then, vent the Instant pot. Check the beef and cow heel for tenderness. Alternatively you can let it have a natural release and pressure down as the instant pot cools.
Let the pepperpot rest for at least 8 hours before serving.