Heat a pan over medium heat and coat with oil. Add onion, then cook for 2 to 3 minutes. Add garlic and continue to heat, stirring, 30 seconds more.
Add meat to pan. Cook, stirring, to brown, then stir in seasoning blend, salt, and pepper.
Stir crushed tomatoes, water, vinegar, spinach and olives into the meat mixture. Cover and let simmer for 5 minutes.
Steam cauliflower until crisp-tender, about 3 to 4 minutes. Place in a casserole or baking dish (I used 9×13) coated with cooking spray. Top with sauce and sprinkle with cheese.
Bake the beef casserole at 350 degrees Fahrenheit for about 15 minutes.