Coat a large skillet with cooking spray.
Add meat and onion; cook until browned, stirring to crumble meat.
Drain well; pat with paper rowels to remove excess grease.
Wipe pan drippings from skillet.
Return meat to skillet; stir in tomato sauce, water, and tomatoes and chiles.
Combine flour, chili powder, and cumin, if desired.
Stir into beef mixture.
Cover and simmer 20 minutes, stirring occasionally.