In a large skillet, brown and crumble ground beef and ground chuck until cooked through. Drain and add to slow cooker.
Add tomato sauce, diced tomatoes, tomato paste, onion, pepper, minced garlic, cayenne pepper, ground cumin, chili powder, white sugar, oregano, salt and pepper to slow cooker. Stir to combine. **See note below**
Cover and cook on low for 8 hours or high for 4 hours. Serve with shredded cheddar cheese and sour cream, if desired.
Notes
Chili will look too liquidy but will absorb once it cooks.
After several reader comments about the chili being too watery, I changed the quantity from two (29 ounce) cans to two (15 ounce) cans of tomato sauce.