- In a slow cooker, add the roast, chili garlic sauce, brown sugar, salt, onion, carrots and apple. Cook on LOW heat for 8 hours. Shred the meat with two forks. Allow to cool for assembly. 
- Alternatively, use leftover pot roast for the pockets or your own go-to recipe for pot roast.  
- Cut each of the four sheets of thawed puff pastry in half so you have 8 pieces. 
- One half of one piece, place about 1/4 cup of mashed potatoes in an even layer, leaving about 1/2-inch border at the edges. 
- Top the mashed potatoes with an equal amount of pot roast. 
- Top the pot roast with two slices of the cheddar cheese.  
- Fold the pocket in half and crimp the edges with a fork to seal in the filling. 
- Repeat the process to make 8 total pot roast pockets. 
- Place the pockets in a single layer on sheet pans lined with parchment paper.  
- Freeze the pockets for at least four hours. Place the frozen pockets in freezer-safe zippered bags to store, for up to one month in the freezer.  
- When ready to serve, preheat the oven to 400 degrees F. 
- Place the desired number of pockets on sheet pans lined with parchment paper. 
- Bake until golden brown, about 40 minutes.