Cook beef, onion, and mushrooms in a large skillet over medium-high heat, stirring occasionally, for 6-8 minutes, until the beef is browned. Drain the fat off the beef. Add the seasoned salt, chili powder, red pepper, and garlic. Cook for 1 minute. Stir in the remaining ingredients and bring the mixture to the boil. Reduce the heat to medium-low and simmer for 35 minutes, until the chili has thickened.