Cut the chuck roast into large 2” square pieces and sprinkle with salt and pepper.
Heat oil in a large skillet over medium-high heat. Add the meat to the pan (working in batches to keep some space between pieces). Cook the meat until browned on each side.
If the meat was cooked in batches, add it all back into the skillet and sprinkle with the flour. Saute for 1-2 minutes longer until the flour is browned.
In a crockpot, layer the onion, potatoes, meat, and carrots and set aside.
Return the skillet to medium heat and add the red wine, heating and scraping the browned bits from the bottom and sides of the skillet. Simmer the wine for 1-2 minutes.
Add the beef broth, tomato paste, and brown sugar to the skillet and simmer stirring until combined.
Pour the skillet mixture over the ingredients in the crockpot. Add a few sprigs of fresh thyme to the crockpot and place the lid on top.
Cook on low heat for 8-10 hours or high for 5-6 hours, stirring occasionally if you’d like.
Sprinkle finished dish with freshly chopped parsley and serve.