Heat a large skillet over medium-high heat until hot. Spray the skillet with cooking spray and add the onion and garlic to the skillet. Cook for 2 minutes, stirring often, until onion begins to soften.
Add the ground beef to the skillet and cook, stirring often, for 5 minutes, until beef is browned.
Add the chopped cabbage and stir to combine. Reduce to medium heat and cover, cooking for 7 minutes, until cabbage begins to wilt.
Remove cover and add diced tomatoes, Italian seasoning, salt, and pepper. Bring to a boil, then simmer for 6 minutes, until sauce has reduced some.
Notes
Each generous serving of this unstuffed cabbage roll casserole is only 3 weight watcher points and 8 net carbs.