Place a large frying pan on the stove over medium-high heat.
Add olive oil to the pan and when the oil is hot, add the onions and garlic to the pan and cook until the onions are lightly cooked and tender.
Add the ground beef to the pan and cook until all the beef is browned. Stir the beef to break it up into small pieces while is cooking.
Set the slow cooker to the low setting for 6 hours.
Add the tomato puree, diced tomatoes, and crushed tomatoes to the slow cooker. Stir to combine.
Add the pink beans, black beans, kidney beans, and corn to the mixture. Stir to combine.Before adding the beans drain and rinse them in cold water. Add the chili powder, cumin, black pepper, salt, and bay leaves to the slow cooker and stir to thoroughly combine all ingredients.*For a spicier chili, add additional chili powder, red pepper flakes, or cayenne pepper Add the cooked ground beef to the tomato mixture and stir to combine.
Place the lid on the slow cooker and let the chili cook for 6 hours, stirring as needed.
Remove the chili from the slow cooker and serve with your favorite toppings, tortillas, rice, or pasta.
