Over medium-high heat in a lightly oiled skillet , heat the chopped onion for 5-7 mins, until it turns semi-transparent. Put garlic and heat for a minute until it’s fragrant.
Put ground beef. Breaking apart with a spatula heat for 8-10 mins, , until it’s browned.
Put ground beef mixture into a slow cooker. Except bay leaf, put remaining ingredients, and stir until it’s well combined. If using, put bay leaf into the middle.
On low heat for 6-8 hours. Bay leaf should be removed before serving.