Chop onions finely
Heat a large pot over medium heat. When hot, add the ground beef, onion, seasoning salt, chili powder, and cayenne & additional spices if using
Cook, breaking up the meat with a wooden spoon, until the meat is no longer pink, 7 to 8 minutes
Stir in the garlic and cook for 1 additional minute
Add 1 cup water, the tomato sauce, kidney beans, mushrooms if using and brown sugar. Stir and bring to a boil
Reduce the heat to medium-low and simmer until the chili thickens and the liquid reduces slightly, 25 to 30 minutes. The chili tastes better the longer you let the flavors mingle (slow cooker is great if you have one)