Beef Cauliflower Casserole

1/2 head medium cauliflower
1/2 lemon
1 pound grass-fed ground beef
1 onion, chopped
1 tablespoon Ketchup
1/4 cup hot water
1 bell pepper, chopped
1 large tomato, chopped
salt and pepper
1 cup Parmesan Cheese

1. Cut cauliflower into bite-sized florets.  Put in pot with half lemon.  Cover with water and boil until florets are tender, but not mushy (15 min usually works).  Drain and reserve.
2. Place gound beef in skillet with a little oilve oil and the onion and pepper.  Stir and cook until meat looses it's pink color.  Add tomato.
3. Mix the Ketchup with the hot water.  Pour into skillet, cover and cook for 10 min.
4. Add salt and black pepper.  Corr for additional 10 minutes.
5. Prehet oven to 350 degrees.
6. Place cauliflower into baking dish when they are still hot.  Toss with 1/2 cup grated parmesan cheese.  Allow cheese to melt into cauliflower.
7. Ladle ground beef mixture over cauliflower.  Bake 20 minutes.
8. Cover with remaining cheese and bake an additional 5 minutes.