I bought 2 chuck roasts from Costco and I slow-cooked them at once. I shredded the meat and made a couple of different meals but this one is my FAVORITE. I hadn't made it in awhile because I go through phases on how I feel about buying puff pastry. I love the way it can change a dish but hate the price. So I was on strike for a while. But this my friends is a must-make!!
My beef was ready to go so in a skillet I just browned about 1/4c each of chopped: roasted red pepper (from a jar to save time), onion, fresh flat-leaf Italian parsley and mushroom; 2 cloves of minced garlic (start with these measurements you can always add more - it depends on how much beef you have left over. I had approx 1 1/2c-2c of shredded beef).
I rolled out my thawed puff pastry - just one sheet. I layered provolone cheese slices (another Costco buy I was trying to burn through), topped with beef and then my vegetables, then another layer of cheese. I folded the sides in and sealed the top and bottom. I cooked it for about 20-25 min on 400 - until it was caramel brown.
It's basically a high-end Calzone but this will get devoured by your family. Enjoy!
p.s. I also had some leftover ham and did the same thing. Layered provolone cheese, then my ham and wrapped it in the puff pastry. Big hit!
I think if you buy a box of puff pastry and make the beef and ham version, they would make great apps to bring to a holiday party.