Optional: Chopped avocado, plain Greek yogurt and shredded mozzarella cheese
In a Dutch oven over medium heat, cook beef and onion, crumbling meat, until beef is no longer pink and onion is tender, 6-8 minutes.
Add next 5 ingredients; cook 1 minute longer. Stir in water, both types of beans, diced tomatoes and tomato sauce. Bring to a boil; reduce heat. Stir in squash; simmer, covered, until squash is tender, 20-25 minutes. Stir in vinegar.
If desired, serve with chopped avocado, Greek yogurt and shredded mozzarella cheese.
Test Kitchen tips
If you're short on time, check the local produce market, as many now offer peeled and cubed butternut squash.
Unexpected company? Ladle the chili over spiral pasta or macaroni to stretch the servings.
Vinegar, added just before serving, helps brighten many dishes, especially rich or fatty ones.