Trim the beef roast and cut it into large cubes. Set them into a large mixing bowl.
Add paprika, ancho, cayenne, garlic, onion powder and salt. Rub it vigorously into the meat.
Heat a large cast iron pan to medium-high heat and add olive oil.
Sear the rump roast on each side, a couple minutes each side. Be sure to get a nice, browned sear.
Add beer to the pan to deglaze. Stir to scrape up the brown bits from the bottom of the pan.
Pour it all into a slow cooker and cook about 5 hours on high heat or 8-10 on low heat, until the meat is fork tender.
Remove the roast from the cooker and set into a large bowl. Shred as desired and cover.
Pour leftover juices from the slow cooker into a large pan and heat to medium.
Process the chipotles in adobo in a food processor until smooth. Add to the pan.
Swirl in flour and whisk to remove any lumps. Continue to cook a few minutes until the gravy thickens. Season with salt as desired.
Serve the roast over your mashed potatoes then generously add gravy over the top. Enjoy!