You're probably not cooking it long enough. Cook the meat first, low, slow heat, but don't add the vegetables till later or they'll get all mushy. When I'm not using ground beef, I use a chuck roast and add a soup bone ( I can generally get one at the butchers) and cook the beef till its fork tender - usually several hours- then take out the bone and pull the roast apart like a pulled beef sandwich. Put it back in and then add the veggies. Not a fast process, but by the end of the day, the house sure does smell good!