Combine the ground beef and Italian sausage into a bowl. Add minced garlic, 1 1/2 teaspoons chili powder, 2 Tablespoons sugar, 1/2 teaspoon garlic powder and a dash of freshly ground pepper and salt.
Using your clean hands or a wooden spoon, mix the spices into the meat until fully incorporated. Brown the spiced hamburger and sausage over medium heat in a Dutch oven or heavy-bottomed pot.
Once meat is browned, add the drained kidney beans, tomatoes, tomato sauce, peppers, yellow onion and remaining spices.
Bring to a boil, then reduce heat. Simmer covered for at least 30 minutes, but preferably longer to let the flavor develop.
Just before serving, add 1/2 teaspoon vinegar, and stir.
Garnish with green onions, sour cream, shredded cheese and jalapeno peppers, if preferred. Serve with tortilla chips.
You can prepare this homemade chili recipe in a slow cooker. After browning the meat in the stove, transfer to a slow cooker and add the remaining ingredients. Cook on LOW for 6 hours.