Use the brown / sear function on your slow cooker (if you don't have a slow cooker, do this is a pan on the stove). Brown your piece of roast thoroughly in a little bit of cooking oil, until you develop a nice crust. Season liberally on the exposed side as you brown. Set aside while you prepare your soffrito.
Saute your shallots, garlic, and capsicum in the meat's juices. Once that begins to soften nicely, add your mushrooms, bay leaves, 3/4 of your parsley (from the stalk up - leave 1/4 of the leaves for later), and saute for a few more minutes
Create a little crater in the middle of your soffrito, and rest your meat in it
Add your tomato paste, wine, and can of tomatoes around your meat, and season with salt & pepper to taste
Slow cook for about 4-5 hours on low
Remove your meat from the slow cooker, and using two forks, shred the meat
Return back to the slow cooker, add some sugar and season further to taste, and cook covered for another hour or so
Stir in the remainder of your parsley prior to serving
Serve with pasta, polenta, potatoes, bread.. whatever starch you're up for
(Photograph is served with pappardelle pasta and Parmesan)